The separation of adult content from non adult content could be a lot better, yes.
But adult content is a huge part of Itch and is paying their bills and financing all the non adult games. If you looked at the top-sellers page with adult content on, it is almost all adult content on the top pages and some games that are also popular on Steam. So it is mainstream indie and adult games, where the money comes from.
I know of Itch's very existence only because of adult games. And that was accidental and circumstance. It is very obscure. I knew several family friendly games that are on Itch, long before I knew Itch. And I even tried searching adult games back then. Very obscure site indeed.