A very large subset of the people using generative AI are people using it for porn. And the people who make those AI models do not want them being used for porn.
Porn and AI is... problematic. Do you remember deepfakes? And how people used them first and foremost to swap other people's heads onto porn actors for the purpose of blackmail and harassment? Yeah. They don't want a repeat of that. Society has very specific demands of the people who make porn - i.e. that everyone involved is a consenting adult. AI does not care about age or consent.
Porn and AI is... problematic. Do you remember deepfakes? And how people used them first and foremost to swap other people's heads onto porn actors for the purpose of blackmail and harassment? Yeah. They don't want a repeat of that. Society has very specific demands of the people who make porn - i.e. that everyone involved is a consenting adult. AI does not care about age or consent.