Well, that's really not fair to BioWare. I'm sure they just had a lot on their plates and our reaction didn't occur to them. (How it didn't. I'm not sure...) But it's very impolite to accuse them of taking the easy way out.
Well said, basically it's accusing them of being lazy, which is a ludicrous accusation to level at any game developers (who spend months working ludicrous unpaid overtime to get games out the door).
That said, I'm pretty sure your reaction DID occur to them. They're not idiots, and their artists and designers as as good as we are at judging hairstyles. More likely they ran into technical difficulties with better hairstyles and were forced to make difficult choices (do we spent x man hours fixing the hair, or other more critical issues? And so on).
That said, concerning The Witcher 3, let's not forget we're comparing apples and oranges here. TW3 has far less customization than DAI, and doesn't have to deal with many of the issues the DAI team did. In other words, it's a lot easier to put a lot of focus on making hair work properly, when your protagonist is predetermined (for example, since you know precisely the shape of his head, it's easier to avoid clipping, and so on).