let's be realistic. imagine for a moment that itch just told Visa and Mastercard "up yours! we're keeping the porn". it would probably have been an existential decision. they could potentially lose nearly all of their income instantly, and their decision would be made at the expense of the entire platform, instead of just the sizable chunk it affects now.
itch has been supporting and hosting an enormous number of NSFW games and media for years, and has been one of the strongest and most respectable platforms for selling that type of content. i think it's unfair to hold them accountable for decisions made by forces much, much greater than them.
creators are the ultimate victim here. but itch's hands are likely tied. if they really just hated NSFW content and wanted it off the platform, they would have disallowed it a long time ago.
please direct your frustration to the source of the problem, Collective Shout, Visa and MasterCard.