It's nothing surprising to me. This is what I assume Reddit was like before heavy moderation of subs many years ago, and what gets on the front page.
/r/trees used to be one of the most popular subreddits and used to frequently show up on /r/all (the 'frontpage' back then), followed by GoneWild communities iirc (at least that's how it felt like, I mean Spez was a moderator for Jailbait after all) I think Lemmy just doesn't hide it and so it's easier for people to click on and such.
The reddit admins did give violentacrez, the top mod of r/jailbait and other porn subreddits, a special "pimp daddy" award, so they are all still really gross people, but I just think it's important to criticize them for what they are actually responsible for.