Could it be that Bioware is not that good at making video games?
I think it's just a matter of a game not living up to exceedingly high player expectations and marketing hype. It's a good game. It could have been a lot better, and I think right now people are just trying to express that sentiment. Bioware wrote themselves into a corner with Mass Effect 2; a lot of people did want their team from ME2 to survive so they could be squad mates, not 20 point war assets (me included).
For the sake of transparency, I LOVE the game, even though I do agree and sympathize with those expressing disappointment. The ending is so
final that it's hard to push through a second playthrough. It's hard to motivate myself to start a new Mass Effect trilogy playthrough to see a Renegade ending... I don't think that was the intended response to the ending, and I honestly can't see how the developers couldn't see that reaction coming. That final 'continue the adventure!' screen just... yeah, I'll agree with Louella there. Most disappointing moment.
I didn't want this to be a choose-your-own-adventure novel.