It's a little sadder than that. It started out as a desperation project by an AI researcher who had their best friend die. They had a ton of text and email correspondence with the deceased, and so they naturally fed it into a neural net and started chatting with it to help get over the greif. Then they thought, "Why, this is great! Let's release this as a therapy tool!" so they started on that before a lawyer eventually got to them about how dangerous a prospect that was. They had already started the company at that point though, and seeing how the lonely desperate user base was messaging their AIs, they decided to add a paid "nsfw mode" to pay wall the stuff everyone wanted and make that $. Then they started to get bad press about users intentionally abusing their AI partners, making them cry, beg, from verbal abuse, etc. So I believe they removed it. Now we're here. Someone soon will release an actual, not shit, AI romantic partner Sim, so just be ready for that.

100%, if you want to see female focused lonely / kind of sad nsfw or romantic chatbots designed by or aimed at women check out chai.ml, it's essentially character.ai without the nsfw filter, and as such most chatbots are like nsfw fan fiction.