I feel the ending is broken, not because I felt nothing, I felt a lot. I think it's broken because it doesn't seem to acknowledge how bleak it is. It ends on a sunset with upbeat techno, that's out of place.
The game forces you to imagine what happens, but the situation you're left with is bleak as hell. It's just uncut despair, not tragic at all, tragedy should have a point.
When you create an unlikely situation that we see play out, we can believe it if it's explained, even if it's unlikely. Because the ending is so vague, what's most likely to happen is the only form of closure we have. We're forced to call back all the obscure lore we might have otherwise ignored because the game gives us nothing more to work with.
What's most likely to happen?. Well, the fleet will most likely starve, except for the geth, who will be mistrusted and go to war, in fact they might all go to war. The entire galactic government will collapse, in fact mercenaries and gangs, people who stayed away from the fight but still have guns will probably be in the best position. So they'll probably rule with an iron fist. The fleet might also just crash to earth (Which might get destroyed by all the rubble anyway), considering the Normandy crashed. And no, I don't think it was directly in the path of the beam, that's unlikely. As for why they up and ran, well I guess none of them really cared about Shepard, and just put up with him to save the galaxy, makes about as much sense as anything else.
And the Normandy is marooned on a strange planet (Because the only just then discovered teleportation) presumably outside our solar system, from which I doubt they will escape, since nobody can make the journey to save them. So they'll all probably die of old age or at like thirty due to lack of medical supplies, and that's assuming members like Garrus and Tali can even eat the food that grows there, those two will also spend their lives as the last members of their species, or that they don't all get killed by whatever might live there. Either way, even if you live (Again, teleportation man, it's just GREAT), you never see them again, and for me, Shepard will probably kill himself, as he makes it clear to Javik that his friends are basically the only thing that keeps him going.
So your crew is fucked, your'e fucked, and the galaxy will descend into a dark age of entropy. None of this means anything, it doesn't have a point other then "The world is shit and nothing you do will ever change that", it doesn't give you any emotional silver lining or closure, it's just pain. Pure uncut cynicism. At least with a corny "Sunshine and unicorns" ending you can just accept it as generic and move past it, appreciate the experience as a whole. Now everything you've sacrificed to protect, every person, every ideal you've held dear leads to nothing through a catch 22. You can't make a situation this bleak subject to interpretation and expect people to absorb something from it, because the most likely course of events is all we have to work with. And the most likely course of events doesn't make for a very satisfying story. What if the entire game was like that? well we probably wouldn't have been able to stop that first Reaper anyways.
It's like you hand somebody a video of someone throwing a baby off a bridge and wonder why their upset, because what you didn't tell them was that it was actually a prop made to look human. They had no way of knowing that, you can't expect them to come to that conclusion on their own. As far as they know, you took a video of somebody killing a kid, they're not gonna want to see you until you explain yourself.
Obviously, if Bioware wants their ending to be shit, fine, that's their right, but I'm done with this franchise then. As much as I love it, returning to it would just depress me, it all ultimately meant nothing. Every time I look at it I feel my gut drop, and I don't wanna deal with that. This isn't about strong arming, I think the ending sucked and I just want it out of my life, like a lost love that turned out to be a serial killer. I've always been big on it being better to have loved and lost but now I'd rather I'd never loved at all.
So I think it's perfectly reasonable for Bioware to listen to criticism the way they always have, and just consider an alternative. I'd be surprised to find that every one of their writers agreed with the ending decision. By all means, keep the endings and add new one on the side if you want, but don't just shut everyone out, if you can't stand by your ending with confidence then why keep it?. At the very least, come out and say "We like this ending, and we're not changing it". If that's their case, then I'd start to doubt their ability as writers but at least I'd know what to expect