I think it's probably just that same-sex relationships simply never came up in the currently-extant stories, rather than some bias against the idea.

In my opinion, there's no reason to force one into a book or the game. Having a same-sex relationship in a story simply for the sake of having one is no better than not having one at all. It weakens and cheapens the story.

If a character shows up, or is already about, who would make the most sense as a homosexual or bisexual person, then that should be what the character is.

~Kashik