Its a fantasy game, you kind of have to get in character and into the spirit of the world, rather than playing it with a layer of modern day political correctness. I mean your playing in a world with dragons, magic, vampires and demons... and the racisim against fantasy elves is whats throwing you off?
My character is a fantasy elf.
edit-
It is all in his perspective.
Why would he want to join the Stormcloaks? They call his people spies. They treat his people like garbage.
But the imperials would sentence him death even when he wasn't even listed to die.
Rashir is chaotic neutral. He joins when he needs to survive. Right now he's doing pretty well surviving.