I guess one part of me would be interested. I mean it would certainly diverge from the usual motivations we've seen from Bioware protagonists. But honestly given Bioware's fan demographic, it'd be leaving a lot of people in the dust, so the other part me would think "they better not."
EDIT: Actually now that I think about it they kinda did have a "Look after your family" motivation with DA2 didn't they? Except you were the child.
Yeah, aside from the "even Bioware's kind of done it" thing with DA2 - and look how well that was recieved(note that I'm actually a big fan of DA2) - the problem is that while it may be different for them, it's very, very standard for the rest of fiction.
I honestly think the issue with the "catering" argument is that I believe most of the writers at Bioware actually enjoy writing homosexual and bisexual romances, and I think that is at partly because so few others in the industry are doing it.
In any event, I'll say this. If the game just flat out did not have romances, I might still play it - I'm still not sold on the game as a whole so it would depend on other factors than just that. If the game only had straight romances, ala ME2, I might still play it. I like that they do representative romances, but the fact is that I probably wouldn't boycott a game just out of protest on that front if it otherwise looked amazing.
But if they did what the OP suggests and force you into a marriage with a kid without having the basic decency Bethesda does to kill them off in the first twenty minutes, that would make me actively avoid the game because that is a story I don't want a part of.