The biggest problem I see with playersexual is the fact that it can hurt the perception of bisexuality as a valid identity. I think the writers handled it well with Isabela, crafting a character who was legitimately open to having sex with people of any gender. Additionally, given how she talks about elves specifically, you might say she expresses pansexuality, even if she never labels herself as such. However, as she is the only character whose sexuality is actually a part of her in game character and she is bi, pan, whichever, she does fall victim to the bisexual who sleeps with everyone stereotype.
Anders however, bothers me more. Why does Anders not mention having a relationship with Karl if he romances a femHawke? Would it really be so 'icky' for a woman to date a man who was bi? If that isn't the reasoning, then why was it taken out? This is the part of the system that bothers me I think, that his bisexuality gets hidden during the pursuit of a heterosexual relationship.
Anders doesn't express an interest in men in Awakening, thats true, but using that as a basis for his sexuality for his entire life is really unfair, and shows that there is a bias in how society percieves sexuality. When Awakening came out, of all companions, how many of them are LGB? None? Really? You sure? Or is it that without being explicitly told who was what, it was assumed they were straight, even if they never gave any indication one way or the other? I'm sure many people aren't looking at it like this, but to lots of people, everyone in the party is straight until very publicly, very throughly outted.
Player sexual does make the most sense. This is ultimately a fantasy video game that doesn't need to have characters who worry about the same sexual taboos etc that our culture has. For those of us who that effects on a daily real world basis, its lovely not to have to worry or feel limited. For those who it doesn't effect daily, then it doesn't change the gaming experience at all.
I think part of the reason it has caused such an uproar is because a lot of people are uncomfortable with the idea of being around that many LGBT people/characters, most likely since they don't associate with that many LGB people on a day to day basis. Many people have, throughout DA2 discussions etc, that it is unrealistic for so many people to be LGBT in one area. Well, if you are a part of the LGBT community, then it actually might be more realistic to be around more LGBT than non LGBT people. And if you aren't, it was hardly shoved in your face. (In fact the only time I lost points with Anders over a romance thing was as FemHawke). Fenris and Isabela, both characters who could end up with people of either gender start seeing each other if you aren't dating one. So, still, even with Isabela, the games arguabley best example of bisexuality, the default becomes a straight relationship.
Most of the games fanbase is straight, romances straight? Terrific, you're taken care of, with maybe the exception of ONE LINE from Anders...which from the uproar they got isn't happening again anyways... If you're LGB or want to RP a character who happens to be LGB, then you're taken care of too. It's a single player experience, so ultimately, (just like with gay people in real life) what gay gamers do in their game has no bearing on your game/life and vice versa.
All of the characters Bioware creates are spectacular, and they all deserve to be remembered for more then who they were romanceable with. Its an important part of identity for characters, sure, but I think allowing real people the chance to engage with their real id, possibly as a minority, is far more important, and a far more admirable use of resources.