Here's my thought process here.
First off, I didn't hate DA2. It definitely had it's flaws, but the entire game intrigued me enough to keep it for multiple replays. And sure, Mass Effect 3 tripped over itself out of the gate, but despite what the internet may tell you, it's not the worst game in the world. So what I'm saying here is that Bioware hasn't screwed up enough for me to turn my back on them.
In addition, I'd like to ask something; Aren't all of these games made by a different development team? I mean, they're still Bioware as a whole, but aren't their separate teams for each franchise? Maybe there's a bit of overlap, but the project leads are mutually exclusive If I'm guessing right. So the quality of ME3 and SWTOR shouldn't have much bearing on the quality of the Dragon Age series. I know we're looking at the general trend here, but it seems odd to compare the results of two different teams when they're trying to create two different things.
I may just be using some insane breed of logic to explain myself, but I'm on the Pre-Order train for Dragon Age 3. I chose to believe Bioware can still make an amazing game, but maybe I'm just an optimist.