I liked the ending to Mass Effect 3 and think people are fucking insane for giving it as much shit as they do. It's certainly not perfect, but come on now. People act as if Bioware really did pull the old "it was a dream the whole time" trick.
A matter of suspension of disbelief. You have it from the audience, you can do no wrong. Once you lose it, regardless of what caused it or how well you were doing till that point, they will nitpick the shit out of your work. Glad it worked for you, but it only began to work for me once I could reject the end choice (ie extended ending). Not that I chose that, only that it needed to be an option. Choice or its illusion was what got me into that universe.
Frankly my dissatisfaction with ME started when I was railroaded on Horizon into making stupid arguments to ensure the Virmire survivor wouldn't be on my crew. I can deal with the Council never believing me, because even the ultimate badass can't just persuade everyone, but I'd think that person of ALL beings other than a love interest would believe Shep's word. Even a Frankenstein's monster version of Shep clearly brainwashed to work for the blatantly evil Cerberus. Heck for that very reason they'd join to either rescue me (either in the literal or double tap sense) or keep just to keep tabs.