I don't think I took it too literally. You used sarcasm which is not well placed. Why was it not well placed? Because you justified the fact that you don't analyze things because they are not new, they are not worthy because not original.
Seems to me that my sarcasm was actually well placed. It wasn´t really aimed at the writing, my target was you. And it was well placed because I refused to engage in a debate, where someone drops a few sentences and then let you go stumbling in the dark of what he´actually talking about. But well, I meant, oh atheism in space, that´s quite played out combined with "so this is proof for the excellent writing how?" But ok, now there is more to work with.
Let's use your comparison with elves in fantasy. Yes there are elves in fantasy, they are not put in every fantasy but yes we can find them quite easily. But is it a reason for no analysis?
Actually no, many RPGs are thieving magpies cribbing things from previously published stuff. It´s not a bad thing as making up a whole species with its own brand new biology, customs, culture, religion and own kind of behavior is rather time consuming and you overlook something pretty easily. Using a "cliché" race allows you to fill the blanks quickly and concentrate on how your elves are different, if they are different. Sometimes it´s not important.
The religion theme is here, and it's not used in every science-fiction piece. It's not because the theme is here that I will not have to analyze how it works. A real analysis is an analysis that tries to find out how it works. When you start saying with sarcasm "how original" you mean "let's not analyze it because it's not original" or when people start to say "they only did it because it's cool, but I have no idea why they did it", or when they use shortcut, it's the best way to misread things.
Well if you started with an explanation why you think the religion theme is important for the ending, people wouldn´t go "huh what?" It´s rather easy to misread something when you only get child= cool ; the essence= cool ; etc. Don´t take it as a personal attack, just an explanation why quite a few people are rather dismissive, when you just drop a few sentences and there are enough people on the net who just troll.
That's why most people think that the youtubers they quote everytime are right. The problem is that some people think that the answers are on internet (if google don't give them answers, so it doesn't exist). Anyway, that's internet. So that's why I got irritated by your answer : it justified misreading (reading while ignoring things in the text ). I don't know if you did it intentionally or not, but that's what you did.
Rather annyoing that some random dudes on the internet invade on your turf with some pseudo literary explanations?
I don´t know if the Youtubers that get posted quite often are using every technical term right, so I take that with a grain of salt. I listened to their opinion to evaluate if I agree with it or not. I don´t think that most of the people here who post them think ME 3 is crap because Smudboy said so. Ok no idea how many people just were annoyed with Shepard´s death and looked for something else to blame the game. But it´s rather annyoing that a big and diverse group of people who share one particular opinion "this game is crap/not for me/dissatisfying" is put together in one big bag, gets a label slapped on "bunch of whiners because they can´t handle Shepard´s death" and be done with it. It´s like using dismissive sarcasm to avoid analyzing the text.
It seems to me that quite a lot of people use the videos as a response because the opinion of the YTer is close enough to their own.
Sarcasm again... As long as you will think that the writers didn't know what they were writing, you will not see the relation between the different element of the game.
For instance, people complain about the ending because it's for them non-sense. actually it isn't.
Well just because you are a writer, doesn´t make you a good one.
I think I use this opportunity to put my own opinion and where I am coming from in here.
I wanted a game where the setting is believable enough, has enough internal consistency, allows you enough room how to do stuff and has an interesting story. You necessarily have to follow the story of course, but leaving enough room for a personal touch leaves the illusion of choice intact. You can´t choose freely, but as long as the choices make sense that´s ok. Starting with ME 2 the game changed tone and became a very different thing. In ME 3 it increasingly became something where I wasn´t really involved in anymore, with BW intruding into areas which were reserved for the player. it turned into something that felt more like BW grabbed my mouse and keyboard and told me "Dude, your input isn´t wanted, because I have this awesome story to tell, now watch it." I got coffee after the first time instead. So maybe they had this awesome thing to tell, they lost me somewhere when I got to watch these crappy cutscenes.
I didn´t expect full participation, video games are limited but why are you intruding into the areas and fill it with some crappy pathos, awkward speeches and feels out of nowhere, sprinkled with some "Shep behaves like some mook in a B movie action flick."
At the end, they grabbed everything. On the credibility level (hope that´s right, I am as much of a native english as you are) Shep behaves like a moron, the whole Crucible thing was complete crap and nonsense, the antagonist/plot device makes no sense, the choices make no sense and the lore went down under a long time ago, together with a believable fictional world. Thanks Bioware, you made your high concept ending but you sacrificed everything that drew me into the game on the way. The Crucible felt very contrived, the Catalyst didn´t feel like it knew what it´s talking about, it´s logic was unchallenged because BW silenced me and why Shep was doing what he doing was a riddle.
Mass Effect was written to impose retroactive reading. It explicitly started with Mass Effect 2 : the retcons. People avoid to analyze things because wikipedia said : "retcons are inconsistencies". The problem is why bioware did that. Mass Effect 2 is full of retcon, its writing is based on that. Mass Effect 3 followed the same path and the ending is a big retcon. So we can't condamn the ending alone it's the whole writing of the trilogy that should be condamned.
Bioware's writers are not beginners, so why did they do that?
That's something I've explained many times but that has been ignored many times. The retcons are related to perception/point of view. We don't know the whole thing, we discover, we understand little by little. The more we know the more it breaks our first idea. The whole thing with the geth is pretty obvious (basically from bad guys in Mass Effect1 to victims in Mass Effect 3).
My my, I have to condense stuff because of forum limits.
They aren´t the first ones who bought into their own hype from the fans? ME 2 had ´s own big shares of problems and ME 3 was great but started with minor annoyances for me which became bigger over time.
The whole retcon are reveals Thing. Sorry but I now commit something that I don´t like myself. Being very vague and claiming expertise without evidence but ah well.
Been there done that, did it better, oh and screwed it up a little, too. Yep I know that storytelling for a small personal audience as a hobby is different than working within the constraints of professional writing. I claim "I don´t get paid for it" as a compensating factor.
Let´s get back from waving credentials without anything to prove it to something more substantial.
In Mass Effect 3 the videos where you see the Illusive man explained the whole writing of Mass Effect 2 : the illusive man tried to manipulate Shepard (and the player was manipulated too : how many people said "hey Cerberus is different in Mass Effect 2 and 3, they changed!"
But in Mass Effect 1 Cerberus was extremists. Cerberus didn't change it's our place, so how we can see them that changed. In the events and outside don't give the same perspective of events).
Manipulated by the dialogue wheel. ME 2 let you some room to disagree with their manipulation even when it was weak, ME 3 dropped even that. TIM played you like a fiddle but that´s more because they took your ability away to disagree. Maipulation is pretty easy when you control the whole world, including what the avatar is allowed to say and do. The only other choice is to uninstall. Cerberus in ME 3 was pretty different and more or less the same. They were the same in a "Cerberus is what we need them to be" way. and that they were human supremacist extremists. They were pretty different because BW wedged them in with a sledgehammer to make them what they needed. I would say that they even dropped the human supremacy angle in deeds, not in words.
Anyway if we go back to essence, the word is used to something that isn't physical. You can't find the essence of someone by cutting him into pieces. So it is something that can't be taken like that. Anyway, in Mass Effect it's an abstraction that turned into a concrete thing. The essence is related to the body. It's no longer metaphysic. The metaphysical concept turned into a physical idea. It's quite hard to understand it if we're on the credibility level. It becomes worst if we talk about essence of species. So this can't be taken on the credibility level. We are here on the philosophical level. But no longer in a Plato perspective (who separated the visible and the invisible, our world and the world of ideas etc...), we are more in Nietzsche perspective where the body is really important, with no real metaphysic. So the synthesis option works the same way : it's related to a body, the synthesis creates a new type of DNA. Here some people think that it's transhumanism, so they think that the game didn't developed it well. The problem is that it's not about transhumanism. The catalyst talked about organics and synthetics, the problem actually more about otherness and perspectives/ representation/ point of view. Once again to understand it we have to be on a philosophical perspective of things.
Do you see the problem here? Plato, Nietzsche, philosophical level, people going in the direction of transhumanism instead of otherness/perspective/representation etc. It might not be to everyone´s taste to be unsubtle, OTOH they marketed it to a mass audience. I don´t say, we need to dumb it down, just consider that a lot of people who played the game have different experiences, different education, interests and different point of views. So it might not be so elegant work with a more direct approach, but it might work a lot better and you don´t have to wonder why people couldn´t follow. Not because they are dumb, they just don´t have a mindlink into the writers brains.
Ok, if your interpretation is the one the writers intended, there is no god, it is a materialistic universe and we got a bad copy of a gnostic demiurge as the highest being and it´s just a matter of perspective, so now what? The big question is reject him, become him or agree with him? Was it only intended the final cornerstone in a series about perspective and different point of views?
Ugh, i really have a problem to formulate what I want to say here. pretty difficult in this medium and time delay. Ok, i see where you are going here and that´s nice. I just wonder why this wide arc and drag God or his nonexistence into the whole thing when it´s about perspective/different point of view, otherness and so on? the whole Reaper conflict didn´t felt like a philosophical struggle. the Reapers had their reasons and they had the bigger guns, no one argued, ok until the end when we got a lecture.
But we can also see earlier something : in the original ending, the catalyst didn't say that he was an A.I. Some people call him the godchild. That's very interesting because anyone who saw him the first time was thinking that he might be a higher being. And He is at the place of God. But we are in an universe where there is no god. And we usually consider god like a father, here it is a child.
So Shepard stormed heaven with a giant lollipop?
Sry couldn´t resist.
Just watched, it´s pretty obvious that it´s a Reaper mouthpiece at least in the conversation.
Just to throw in some food for thought. Ever considered that you are seeing connections which aren´t there or weren´t intended?
Hm, there is obviously no god?
Let´s see If I can fake a believable christian fundie of the evangelical bent.*cough* *cough* *ahem*
Of course there is God, the aliens just haven´t accepted Jesus as their Lord and Savior. The soulless Geth worship a false idol, because they were fallible mortal creations. Benezia doesn´t see the light because she never accepted Jesus in her heart and so she goes to hell (enter some other similar stuff for other denominations).
The Reaper War is the final reckoning, the Catalyst the antichrist who leads the people of the galaxy astray. The Shepard is the tool of our Lord to fulfill his will, it´s obvious. No one could have succeeded so spectatularly without the grace of God.

Was there a point to this exercise, besides being funny? Weren´t we talking about perspective/point of view? And ok, I am silly sometimes.
Anyways I put the whole religion angle more into world building and the Reaper worship as some kind of reaction of "people" coping with the presence of an overwhelming entity they don´t understand. So huh, religion and spirituality isn´t an organic exclusive thing, interesting touch. I had a certain feeling that the Benezia situation was some attempt to communicate it, OTOH I don´t consider near death experiences, which some people had, as proof that God exists, their absence is irrelevant.
And well God´s nonexistence/aliens as gods in the setting was a nice piece of world building, but I didn´t put it into the central to the story category. Perhaps as a hint that there won´t be a higher being to bail us out. Actually pretty important but different from your interpretataion. I can see where you are coming from though.
I don´t intend to be mean but I throw it in the ring. Earlier you said that the retcons are a thing of perception/expanding the point of view. Isn´t the extended cut more or less the same thing? It sounds a bit like "I don´t like it so they gave in to the masses but the other stuff is ok because I like it."
Perhaps a bit word twisty, it just crossed my mind when I read it, so why not throw it into the debate? 
The way we have to understand the essence think is the same we have to consider some element in the ending. So if the essence thing is not liked, it's impossible to like the ending. But there is a coherent line that has to be followed because it's how Bioware made their game.
Anyway, Mass Effect is written like a puzzle, things has to be put together to see how they work. When we separate things they are not interesting, and it's not Mass Effect.
If that was their intention, they hid the pieces too well. IMO they tried to go high concept and failed. To be blunt, the average writing in the games feels more like something out of an episode of Arrow or The Flash, I actually like the series but they are action flicks.
Is it written like a puzzle or do you want to see it as a puzzle? Other people puzzled IT out of it after all.