Why is it acceptable to say you're not attracted to someone too short, or with a big nose, a bald head... but not acceptable to be unattracted to someone with a different skin color or cultural background?

Because questions like these often royally piss people off and often evolve into personal attacks on the OP, I’m going to start by saying I am speaking generally here… not about myself or anyone that I know specifically.

There isn’t a lot to elaborate on… if the color of one’s skin is just another physical attribute, why is it racist to not be attracted to a certain skin color, but perfectly acceptable to not be attracted to the size of one’s ears or the shape of one’s chin?