> It's negatively impacting people and servers that have no interest in having anything adult on them.

So who should police that? I am in certain communities that try to be stricter on moderation (which I love!) but it's hard work, lots of people trying to be at the edge of rules (with normal things like swearing, insults, etc.).

Whoever labels adult only and does not care is not wishing to put the effort to police that it actually is not.

Personally I do generally mind much more annoying, aggressive, stupid posters (in various channels), than the fact that I am not allowed to post some stupid adult-looking meme.