I don't know, but does anybody really think that 10 or so minutes long rap battle between Shepard and TIM and then 10 or so minutes long information dump from the Catalyst, then crawling to pick red, blue, or green with subsequent slideshow is an appropriate ending for an action sci-fi RPG? Are there really people who play through it for the second... third... fourth etc. time and think, "This is so epic! This is so much fun! So much variation!" Because if yes, then I honestly envy them. Big time. I've replayed the games three times so far (and I love them) and ME1 and ME2, even if flawed, always make me feel like, "Hell, yeah!" at the end. I wanted to like ME3's endings so much, but I ended up most disappointed I've ever been over a game's ending when I got there, and they just keep feeling meh.
When I played the first time, I expected to be blown away. I expected something along the ME2's suicide mission where everybody would come together to kick some Reaper a*s*s. The companions have always played a big role in ME. It's one of the things BW does so, so well. So why were they left out? And this was to be the end of the trilogy. It was supposed to be epic. It was supposed to be fun.
Instead, I was confused (What's going on? Why is there a new and omnipotent character introduced in the last minutes of the game? It's lazy. It reeks of the writers grasping at straws and not knowing what to really do with the ending.), frustrated (I couldn't call the Catalyst out on any of its bull***t and there was a lot that needed to be addressed. Many times I wanted to say, "Well, that's simply incorrect." Not a chance.), bored (WE. STAND. THERE. FOREVER. AND. GET. INFORMATION. DUMPED. ON. US. IN. THE. LAST. FEW. MINUTES. OF. THE. TRILOGY. Right after we spent ages talking to TIM, talking to Anderson, with just some cutscenes thrown in between. So very epic... not.).
I wanted to talk back because we basically proved the Catalyst wrong in many ways throughout the games, not to even mention its logic is rather erratic, and yet we can never bring it up, pretty much. Shepard called out Harbinger and Leviathan on their bull, why not now? Why trust it at all? I don't want an awesome button. I don't want a button that solves all my problems. I just want stuff to make sense. I want a super ancient über intelligent AI to act the part. (It actually compared fire, a thing, to sentient beings. The hell? It actually dared to tell me there is no war, yet the only thing we see the Reapers do in the game is turn everything into either dust or abominations that shoot at us. We don't even see any harvesting. Hell, the Collectors did much better job at harvesting than the Reapers ever did. CERBERUS on Horizon did a much better job at harvesting than the Reapers ever did. EDI once brings up some slave camps which we never get to see. The asari in the hospital mentions something. That's all. The Reapers just destroy stuff. And they develop troops to do so. Their beams pretty much vaporise people so there's nothing left to harvest. If that's not warfare, then I don't know what is. This is completely brushed off by that very poetic "Like a cleansing fire..." line that makes me want to facedesk and knock myself unconscious.) I want Shepard to act like Shepard. I don't want the ending to break our character, the game's lore and step on what we've learnt throughout the game.
Real people wrote that ending, so blaming it all on "Reaper logic" is an excuse. Some of it? Sure. But those people decided it was appropriate to present synthesis as the "ideal" solution (Strongly indicated by the writers as the best option because it's only available with high EMS, so it's meant to be a reward for all your hard work.) while the theme of ME3 is overcoming differences and uniting the galaxy without ever needing to erase those differences. It is insulting and inconsistent, and it shows they weren't capable of keeping their stuff together. (BTW, I also love how the Catalyst tells us it's already failed a few times but, hey, it'll totes work this time.)
Also, if it's the synthetics who always turn on their organic creators, why not just collect the bad guys? What? Too simple?
Plus, space magic. Somehow, three buttons weren't cool enough, so we were provided with three pretty absurd ways to turn the Crucible on. I'm really glad I don't have to turn my coffee maker by shooting it... or dissolving in it... Like, okay, I miiight believe the Control thing. Shepard turns into an AI SOMEHOW and takes control over the Reapers. Because having a console or something to do that is too lame. Because telling the AI, which just told us it controls the Reapers, to cease the attack is too lame, as well. (It is willing to help us Destroy them, so nobody can pull the "But.. but... that wouldn't be a permanent solution to the organics vs. synthetics conflict." The AI tells us that with Destroy, the conflict will continue and it allows us to do it anyway. It cannot stop you from throwing the controlled Reapers into the sun later, either.) However, SOMEHOW dissolving to provide the Crucible with "our energy" and then SOMEHOW overwriting the DNA of existing beings that are in no way connected to the Catalyst or the Crucible... What? WHAT? Activating the Crucible by shooting a magic glass barrel is cool, too. It's even cooler that Shepard walks right into the explosion for some reason. Because, you know, people normally do that.

^^ That gesture expresses perfectly how I felt and still feel when I think about it.
Plus, why does the kid look what it looks like? Can it actually read people's mind or what? This made sense in the geth consensus. Here? Why? But, okay, let's say it can really read Shepard's mind, but then if it was done by the team to stir an emotional response, why pick the kid that Shepard saw that one time for like a minute? Why not pick Shepard's love interest? Or their friend? Anderson? Or copy Shepard's appearance? Same with the dreams. Did anybody actually care about the kid? I mean, it's so forced. We have zero connection to the child. We see so many people die, why should that one be special? Oh, no, wait, I forgot - it was the only child on the whole planet...
But the worst thing is that they had a wonderful place to stop right after Anderson died, which is exactly what many ending mods work with. The Crucible could've just fired and the results would have been decided according to the decisions we made in the game, just like ME2 handled it. But no, they decided to drag it for further 10 or so minutes for some obscure reason and give us a little glowing kid that dumbs the Reapers down. Sovereign was right in the end. That's really beyond my comprehension.
And that's just a few things off the top of my head right now. I could probably come up with more stuff with some time, like how we get to see Jacob, Jack, Samara, Zaeed and some ME2 crew post-war doing their stuff, but the last we see of our current crew it's them being all sad during a "funeral". The fact that if Shepard survives, it's pretty much not at all addressed. Etc. But I'm probably long past the good time to stop myself. I hadn't really had much chance to vent about this much. But I think I'm somewhat done for now...
Sorry for the long post. However, see what I mean? Whether Shepard lives or dies is the smallest problem we could possibly have and I can't believe some people are still hell-bent on this "They didn't like it because Shepard died and there were no unicorns."