This sounds more like an Itch.io issue and not a "NSFW Is on the platform" Issue.
It is not that hard to make the UI do what it's meant to do and restrict tags to certain accounts. If itch did their job right, this wouldn't be an issue to begin with and you could have the best of both worlds; having a SFW Marketplace and also restricting games to certain demographics so you don't run into the issues of Games being suggested to the users it shouldn't be marketed towards.