A lot of it is misogyny, especially in the case of so called titty streamers that are really just women wearing normal clothes (leggings, tops with midriff) and then being hypersexualised.

However, I also think some of it's because in a lot of cases these people are shit at the games and not very entertaining. At the start of it I remember certain 'titty' youtubers were using fake gameplay. Their content is more based on sexual parasocial relationships. It doesn't really belong in the same space as a bunch of other entertainers.

Twitch has a some streams that are literally a woman in body paint or pasties jumping for money. Some (not all) of the titty streamer complaints are about this, not women playing games in a swoop neck.

AFAIK the most recent rule changes don't address this, it's still allowed, but you can't stream yourself drawing a naked person.

Doesn't really fit into my point, but here's the funniest ban during the brief window where drawn nudity was allowed: https://x.com/baalbuddy/status/1735397897242579068?s=20