Because they don’t like the fact that the majority of custom content for uncensored models is hardcore porn.

Which honestly is rather silly for the companies making the models. The cat's already out of the bag, and if a competitor manages to make a similar/good-enough (uncensored) model there's nothing midjourney etc will have going for them.

Or as someone once said, if they took porn off the internet, there'd only be one website left, and it'd be called "Bring Back the Porn!".

Isn't that where generative AI seem headed anyway? Censorship is ramping up fast, and hype is dying down faster.