Yeah, I pretty much agree to what has been said so far...
We can't make avatars and characters to match every person in this world.
Also, we have to remember that game characters are often idealistic portrayals of what a hero would look like in that particular game. If you dont like the setting, then don't play it.
We need to learn to be stay cool and be accepting of these setting, the way we would just watch movies with white american macho marines saving the day whenever there is a crisis.
Games does not take time to discuss their sex life, just as much as they usually dont care what animals they like, how old they were when they were first able to ride a bicycle etc.
Unless the story line of the game dramatically changes due to the character's sexual orientation (example, if youre straight, the zombies will try to eat you, If youre gay...they will still try to eat you), I dont think developers should waste time on creating such characters.
But hey, if there comes a day when more gay people are involved in game development, things may change and when it does, i am all for it.