...So does classical literature. So do movies. So what?
Look, I'm a chick and I really don't mind that there are not exactly 50% of games with female protagonists out there. I don't really CARE about the ethnicity/whatever of the character I play. If there's a choice, by all means, make your game allow for the choice of various different ethnicities, but if not... Seriously, I could not care less.
The preset character I became closest to in a game? A nameless, scarred immortal MALE of indeterminate ethnicity. In other words, someone who was most certainly not me. If game designers could just focus on making a fleshed-out, well-dimensioned character, I'd be thrilled. I don't honestly care at all if the character looks like me, as long as I can connect with them. I wouldn't care if a game shipped with a main character that basically WAS me if it wasn't fleshed out well. There is an order to these things. First, fleshed out character. Somewhere around LAST, social diversity.
Oh, and didn't you realize? We can't have kids or even sometimes innocent females or old people in games. Someone might kill them! Think of the goddamn children!
Do away with that piece of nonsense, and maybe you can have more diversity age-wise. Until then, just bloody deal with it.