Those who gripe about such things have their own cognitive distortion... they have ingrained behaviors to value physical attractiveness (and fitness) beyond any utility it might provide them.
Are you going to hate the fat girl's personality so much that you can't stand her? Probably not.
(Apologies for being crude) Is her pussy going to feel like sandpaper on your dick? Probably not.
You mistreat such people because you're afraid that if you were to become involved with them, your social status would decline. But the only reason humans care about that is because of mating prospects.
Your truths are subjective, and self-harming.