These series always have a designated punching bag race that never catches a break. I'd be one thing if they lost a major war, but if they're a less "civilized" people living in grass huts, it gets touchy. It implies the differing treatment isn't simply discrimination, but an inevitable result of their differences in development. Those conquered peoples disappear from history as they're simply integrated into the common population of the victors but something like pointy ears and tails would become yellow badges.