We've been over this on the forum. The benefits of versatility that come from playersexuality seem to outweigh the costs to immersion. Imagine if there was one heterosexual, homosexual, and bisexual option per gender of companions, and it wasn't the one you were interested in for your playthrough. Now you're railroaded if you choose the one prescribed for you, or railroaded into changing your character to the one that is viable for the playthrough you have in mind.
Don't think the player's sexuality matters at all. In fact, I don't think I've ever played a game which catered to the romantic interests of a player base like this. A male character couldn't romance Alistair in Dragon Age 1. Same goes for a female character and Morrigan. Characters oughta reject you on the mere basis of your genitals, regardless of what the player wants.
