There is a lot of effort put into those ERP models, lol. The training and datasets are actually really good, hence they are very good at the non-e RP part.
The eRP community was apparently going strong before Llama or Stable Diffusion were even a thing, using GTP-J finetunes and some even older base models. Llamav1 was like a Christmas present, and all the UIs and infrastructure were already set up to work on it.
That was a strong motivator for all the work on Stable Diffusion too.
Oh, yes, I do know that this scene is quite large. I still remember the drama of when AI Dungeon began cracking down on NSFW content due to model licensing (?), or the thermonuclear response that followed character.ai doing something vaguely similar.
It's more that I always pictured AI developers (especially ones that interact with models directly) as these very intelligent, selfless scientists - and not ordinary people who are okay with using these technologies for more "hedonistic" purposes, so to say. Nothing wrong with it obviously, and I'm really interested in seeing where this stuff is headed for in the future.