It's human nature actually. All animals want to look for the best "mate" and ones that have a better appearance are generally better mating partners. Sorry to say it so harshly but that's the way it is. Most girls will do the same thing with guys. They want the guy that looks as though he can be a provider, someone to keep you safe.
It's all beginning to be superficial now as more and more women are becoming the main worker for the family and more fathers are becoming stay at home parents.
Still, that's the way it is and probably always will be. People will always be judged on appearance weather it is guys judging girls, girls judging guys, girls judging girls, and guys judging guys.