Um...why is this weird? The player has control over whether they want to wear a swimsuit or not, and who to wear it for. You don't have control over someone seeing you, apart from hoping the mod only works with specific pieces of clothing. As for the people modding...um no bloody offense, but if you ever have been part of or know any erp scene, you know its a very mixed bag of people who do it for various reasons and are of VERY varying mental stability. People thinking its all kittens and rainbows really surprise me. I'm not talking mods in general, just this specific one. And yes, some people use it because they want to see people's characters like that. Some do it respectfully, but it wouldn't surprise me otherwise.
I mean, you lost me at the commission thing because if you draw, yeah some people try and get work done nonconsensually with other people's characters. Not many, but enough where you better make sure both people are ok with the drawing. It's not everyone, but you're not pearl clutching if you require people to be on the up and up either.
I don't think it's a widespread or solvable problem, but it doesn't take everyone to really screw someone up, just a handful of people. I don't think people should really pooh pooh this, but its a very thorny issue that has no real answers to it.
I don't know about proof, but I'm not sure how you know she has none. Keep in mind there are a lot of sites for that kind of content.
As for modders in general, no they don't. I thought this was specifically about one type of mod, but it seems you are thinking it is a false flag to get all mods out?
As for "you are not your character," I don't think it's that easy. If someone creeps on you online, it doesn't always make it better that it's just pixels. It also depends on the person, I mean, some people may honestly have dealt with harassment both sexual or not in their lives, and loss of control can be very bad. You're kind of handwaving it away some, in order to defend modding as a whole from being curtailed. I don't think it should be, but this specific issue is unique and can be dealt without judging all modders