It’s there to get it away from the other categories. Every category isn’t just a game, there’s other stuff like events, just chatting etc to cover any content that isn’t specific to a single game (like a gaming related podcast for example), so playing a game isn’t required you can just talk at the audience. People who make the sexual content were using those more generic non-gaming categories (as well as popular gaming categories but having the game running in a tiny box in the corner) but advertisers took issue with advertising on the sexual streams, so Twitch made ways to segregate them from the content advertisers wanted to pay for.
Go to the IRL or Hot Tub sections and find something that isn’t softcore porn.
… why is there a Hot Tub section on a gaming site, and what else would it be for?
It’s there to get it away from the other categories. Every category isn’t just a game, there’s other stuff like events, just chatting etc to cover any content that isn’t specific to a single game (like a gaming related podcast for example), so playing a game isn’t required you can just talk at the audience. People who make the sexual content were using those more generic non-gaming categories (as well as popular gaming categories but having the game running in a tiny box in the corner) but advertisers took issue with advertising on the sexual streams, so Twitch made ways to segregate them from the content advertisers wanted to pay for.