Regarding the Willy Wonka meme of "can you come up with somethin better?" ...people don't have to. Doesn't matter what they're criticizing, no one has to come up with something better when the criticize a piece of work if they don't want to.
If someone views/plays/whatevers a piece of work and says "this doesn't make any sense and I don't like it"... that's good enough. Why? Because if we go through the critiques of everyone on the planet, both professional and amateur, the great majority of those people critique works without giving an alternate take on them.
A lot of the time, if something makes 0 sense and there's no justifiable reason why it makes 0 sense but still fits into the rest of the work, the person has a right to say it sucks without coming up with their own take.
If we don't have that right then we should all shut up and not say anything bad about anything, ever. Cause every one of us here doesn't like something and has given an alternative take on EVERYTHING they've critiqued.
Why is bad music bad? Cause it is. End of story. Should we all sit around trying to solve Nickelback's problems of why they suck?
But in terms of Mass Effect 3. After all this time I'll say this about it. It's not a BAD game (Metroid: Other M is a BAD game). It's a bad RPG, It has a bad ending, and it gave me no motivation to go back and replay the trilogy over again so I could play through an entirely alternate take of the three games because there was no point to doing that. So while it's not a bad game purely for the sake of being a bad game... it did diminish the impact and purpose of the games before it and that's why I don't like it. And no, I'm not writing fan fiction about how I think the game should have ended unless you're willing to pay me
I'm already working on other stuff for free for this place