I actually like being able to play after a game's ending, so I don't consider that a bad thing.
That said FF VII can't be compared to ME3 largely because FF VII despite being part of a series was a stand alone story, it was not dragged out into multiple games that showed that by all rights the developers should have been able to end it properly. It generated a lot more investment.
What's more FF VII sort of helped pave the way for this, because eventually Square Enix decided they really couldn't just leave things that way. They ended it properly 10 years or so later, for an additional fee, which sucked, but it was more or less them surrendering to something that should have been obvious to begin with.
People realize that Bioware pretty much needs to do the same thing, and what's more should do it NOW instead of making us wait a decade, and then charging us for an ending that we should have gotten to begin with. With Squeenix at least you can justify what they did a little by them waiting so bloody long and having to pretty much assemble a whole team for it. With ME3, Bioware is still together and working with that specific property given their franchise plans. What's more after what happened with FF VII, they should know better.
There is also the issue of the developers, and the fact that they intended for ME3's ending to go down like it did, and intentionally lied about what the ending was going to be. With FF VII no promises were made ahead of time, and I got the impression that the developers didn't really see it coming. What's more, unlike ME3, FF VII was not making any pretensions of giving you choices that were going to matter... where that was part of the entire gimmick behind ME3.
As a result, ME3 does stand as the worst video game ending of all time. All efforts to say otherwise by "No Right Answer" and "GinxTV", ME3 managed to create whole new directions to suck in when you follow the whole issue. I won't say other endings won't suck more, but this is easily the biggest dog turd of an ending that gaming has ever seen.