And banning posting candid sexually suggestive photos of kids helps to prevent the subjects of the photos from getting harassed at school when someone finds the photos online. I don't see why that should be any less important than trying to prevent harassment of people who take and post those photos.
At least the person who gets harassed over posting the photos is getting harassed for something he actually deliberately did, whereas the kid might be getting harassed for accidentally showing some cleavage or some underwear. Or maybe it is ultimately the kid's fault for not dressing like a Saudi woman when in public.
Or you could just answer my question.
I was specifically not litigating the enforceability of "creepiness" standards.
For what it's worth: Watching anime isn't creepy. Two males kissing isn't creepy.
What is the long-standing issue that you would be preventing though? It's creepy and wrong to be sure, but say banning a specific subreddit with that content, what is the result of that action?
With doxxing you have documented cases of people being harassed based on people finding out their true identity. So banning doxxing helps to prevent situations where people are harassed outside of the site for the things they do on the site.