Hmm. I suppose I don't see it, but I play with adults. And my regular group is pretty evenly split when it comes to gender and sexual orientations. Disconnecting ones own preferences from ones characters doesn't seem that hard to me, either. In my games, I've had a straight(ish) male character played by a gay(mostly) man end up with a straight female character played by a straight dude and nobody thought it odd. If your experiences are with a more juvenile crowd, I sympathize.