hint: they are all about one thing and there are a lot of eager volunteers to help on those websites. It would be easy to "normalize/clean/classify" because the pictures would have a consistent theme, thus reducing the amount of parameters.
We are not trying to generate elephants getting railed on a SpaceX rocket flying in oil painting style (although I'm sure theres people into that and its not my place to judge), we are just trying to remove the human cost out of this necessary evil.
I can't believe nobody is investing in "DALL-E-2-4-PORN". This sounds like an X amount of money thrown at a hugely sticky product that can be iterated (with the current trend in hardware) to the point where it literally generates billions of dollars in revenues for ages to come (no pun intended).