Well, I can honestly say that my opinion towards Bioware wouldn't change if DA:I turned out to be lackluster (it looks awesome though, so the chance of that happening seem to be rather small). I buy games based on whether I find it's content appealing or not (bought ME1, ME2, ME3, DA:O, DA2, did not buy SW:TOR). When I decide whether the content is worthwhile or not other gamers opinions are not worth squat to me. Also, I never hold a bad game against a game developer, and instead prefer to look at each game without being "tainted" by previous experiences. I do however keep in mind whether a game developer has produced any worthwhile games previously, which influences me positively.
And since Bioware has produced plenty of great games (ME2 was legendary, ME1, ME3 and DA:O was awesome, DA2 was very good), I will always keep an eye on any game they develop.
So no, I won't "give up" on Bioware if Dragon Age: Inquisition isn't as good as the previus games I have bought from them. That kind of reasoning seems illogical and does not have any place in my mind.