Come on, Ieldra, BW gave you synthesis, what else could you possibly be unhappy about? ![=]](https://lvlt.forum.bioware.com/public/style_emoticons/default/sideways.png)
And that I appreciate, indeed. The thing is, as people - you, among others, iirc - have pointed out, that this ending doesn't exactly fit the tone of the story that came before, and it's riddled with religious imagery on top of it.
As for those messages I detest, here are twp:
(1) Shepard is written as simple-minded. Rarely if ever do we have the opportunity to debate the intricacies of a situation. Every problem is simple in the end. So much that the one time you can come up with an elaborate idea stands out as almost alien - dealing with the "Indentured Servitude" in ME2.
So this person, who is apparently unable to look beyond "The Citadel? The fight's here" and suchlike, who is unable to appreciate the situation the Council in ME3 finds itself in when they refuse to let go everything else in order to take back Earth - this is the saviour of the galaxy? It boggles the mind... possibly you don't have to be stupid to save the galaxy, but apparently it helps.
Playing against that impression was about the hardest piece of work I ever put my imagination to.
(2) Reaper technology and its indoctrination gives off a strong vibe of "things we aren't meant to know". The EC version of Synthesis completely subverts this in the end, but for almost the complete trilogy that came before it remained intact, as everyone who dealt with Reaper tech ended up indoctrinated or dead, and anyway except when it involved weapons - see the militaristic vibe again - everyone who even thought about adapting it to their own use was at least morally questionable, if not outright evil. That Shepard themselves owe their life to the maybe most impressive technological achievement in the ME trilogy is swept under the rug and dealt with in an off-hand manner.
Quite probably this was not intended, but between Reaper tech, the genophage plot, Miranda's background and a few other subplots of the "cautionary tale" variant, ever since ME2 there is a message that technology shouldn't be used to change people, almost to the point of "life sciences are evil". Shepard is exempt because they're the Chosen One, and they die in the end anyway or have their altered parts removed from them, so the message most definitely stays intact until the Synthesis option comes along and confuses everyone with a subversion that has no roots in the story that came before. This is the part I really hate, not because it exists, but because I don't get the roleplaying options to make a stand against it.