The rules of Itch are clear

I think it is a little bit more complicated than that. Obviously you can pay for nsfw content with something like paypal, otherwise you would not be able to pay on Steam for that type of content. Or am I misinformed about that? Same with Patreon. Lot of smut there too. Or can't US citizens pay for their cartoon smut on patreon?

Also, paypal does not even ban nsfw content. It bans cigarettes though. But you have to have approval according to their tos. And I guess they would deny that approval depending on your location and if you are a business with valid tax information or just an amateur. But if given you could sell actual real life porn downloads/streams with friggin paypal. Yes, there are sites that do sell that and you do can pay with paypal there. So this whole cartoon smut situation is ridicoulous. Itch should business up and do it like the grown ups or at least offer an optional way of handling this, instead of driving business to Patreon, Steam, Nutaku and others.

The gumroad thing, well, they disallow a lot of content, like homemade food. But you also can sell a lot more stuff there.

my issue is that while the itch rules say that you can sell adult content as long as you adhere to paypal rules, which state that "certain sexually explicit materials" are banned (with no elaboration on what "certain" means, though some further investigation says that digital goods are banned- like the ones sold on itch) and then others need permission. does this basically add up to "you can sell what you want but if you get caught we're tossing you into direct payments", which also uses the same payment processors that have this stuff banned in the first place? it doesn't add up. 

i agree entirely. the silence on this is very disconcerting