When they usually aren't all that classically attractive themselves.
So stupid. And it makes it seem like they worship attractive people.
Bella ramsey would be an example in which a bunch of chud nerds call her ugly constantly meanwhile they're not exactly lookers themselves.
Because in their worldview a woman being ugly is morally wrong. Every woman has to work to be as beautiful as possible and anyone who is still ugly no matter how hard they try just got unlucky and should basically be shunned and pitied. They hate the idea of acceptance of a wide variety of appearances in women because that makes it more likely that women will put in less effort to be beautiful (which, remember, is not only a bad thing in the abstract but a morally wrong action).
They see it the way we see pro-cop media. It's glorification of something morally wrong.