I would amend that a little to say "trying to tailor a sequel toward people who didn't give a shit enough to play your first game, to the exclusion of the people who did is fucking ridiculous".
There are arguments to be made in favour of catering exclusively to an existing fanbase (and in principle I support the idea, even though in this case it would probably mean I wouldn't touch DA2 with a 20-foot pole taped onto the end of a 30-foot pole), but from a business standpoint, if you don't try to broaden the game's appeal you're almost definitely going to see stagnation in the game's sales.
The thing is though, that definitely doesn't require you to alienate that preexisting fanbase. There's always going to be a group of curmudgeonly old fans who will react violently and negatively to any change, whether it actually affects what they liked about the first game or not, but you can definitely keep the soul of your game intact and deliver to the majority of the fanbase while still branching out to new players - look at how Dead Rising 2 turned out, even with all the esoteric design decisions that were kept from the first game.
I don't even think Bioware necessarily failed at juggling those two goals with DA2, at least going off of what I've seen/played so far. It's more that they've made so many ridiculous blunders in speaking publicly about the game that its perception among the fanbase gets more tarnished every time they open their mouths. Going on about how much work has been put into improving the graphics only to come out with "Shit Mountain" as the first thing anyone sees is going to create a first impression that's hard to bounce back from. The "Fight like a Spartan" nonsense and trying to show off the game as an action RPG is one hell of a backfire - people who want tactical combat are going to go in expecting and looking for ways to see it as an action RPG (when for the most part the only differences are a zoomed in camera and defaulting the console versions to what is essentially just a gimped version of the normal auto-attack that requires maintenance), and people who are initially attracted by the idea of an action RPG are going to notice immediately that all they're controlling is a gimped version of a normal auto-attack that requires maintenance. "Press a button and something awesome happens" just sounds stupid and condescending, when all they really mean is "the combat animations should have more flair".
You can just go on and on, through goddamn near every single thing they've said. If you take the PR at face value, it sounds like the game's received a more drastic overhaul than from Mass Effect 1 to 2. In reality, I'm fairly sure there have been expansion packs that introduced more drastic mechanical changes than the ones made from DAO to DA2. Perception of the former is going to piss off old fans, and the reality of the latter is as likely to make the people who hated the first game feel duped and irritated as it is to draw them in to the franchise. I think once the PR is over, there's going to be a pretty big contingent of old fans who realize that it isn't really all that different, and I think there are actually some definite improvements that will bring newbies in and satisfy people who had certain issues with the first game, but that's all going to happen in spite of the PR, not because of it.