One could argue that EA is also at fault here, they are the ones who decide when the game has to come out. Didn't Bioware have to beg EA to give them more time during the developement?
With maybe a little bit more time they could have done better.
Well, in terms of the gamebreaking bugs, quest bugs, campaign related issues, etc, those are things they should have expected, as should we, because in a game this complex and big, there's no way they could have found everything in house. Or tested on all possible pc configurations, with all possible software people have running.
This is where a beta would have helped, however, how do you let people play a beta of a story-based game? That's not cost effective either.
No, the fault in terms of the pc control scheme lies, IMHO with the design team. They made a conscious decision to leave it till after getting the console controls in place. They painted themselves into a corner, and that's why you see things like poorly designed menus, no native mouse support, etc.