There is not nearly enough 'definition' for the differences between characters and in my opinion, having characters with set personalities and set sexual preferences gives those characters a deeper and more realistic feel and at the same time gives us as LGBT players a definite feel of 'yes we do exist in this game' instead of just the shared pallet where every time we argue for the existence of such characters we just get slammed in the face by 'Player-sexual character not homosexual, get your gay **** out of my *Insert product here*.'
I've never heard that "no gays b/c they are player-sexual' argument brought up, tbh.
I prefer the "player-sexual" thing from a strictly game-play standpoint. I like having the ability to romance the character I like the most or is the best fit with my PC vs. the one the devs arbitrarily choose to be 'the gay' or 'the bisexual' one. I guess it depends on how you approach these romances. I will only pursue romances if I like them and won't do the romance that's available to me just because it's there. Some people may be different and will do whatever romance is available just to do it.
On that note, I'm all for representation of LGBT characters but prefer it done with non-LI characters. For starters, interaction with these type of characters typically can't be avoided. With an LI on the other-hand, those that choose not to pursue that romance probably won't even know that the character is gay/bisexual/etc. By doing it with an LI character, it seems as if the LGBT content is being cornered off into an optional part of the game that most won't have to 'deal with'.