They want their specific content shown to as many people as possible. They don't want to have their content limited to over-18 or NSFW websites.
The thing is, I think that the content-hosting platforms' broad "NSFW content is not welcome" rules is great. While I may not object to seeing a male nipple pop up in my feed, I won't object if male nipples never pop up either.
It is working the way I want it to, but it sounds to me that the complaint is that I should at least see this type of content occasionally even if I don't seek it out, which seems completely bonkers to me.