I mean, if you’re genuinely asking, a lot of it is believed to be due to the severity of sexual repression in most of the world. Rape is one of the most common sexual fantasies, with 20-50% of the world’s population experiencing them.
Most fetishes come down to the loss of control or the gain of control.
Human brains are complicated. This is just from my understanding, some may agree or disagree, but the line of fiction and reality is a safe space for them. Some r-pe and SA victims read/write stories like this to process their trauma (I do suggest reading studies dealing with this, it personally helped me understand so much :]) Some have a fantasy to be taken advantage of and some dont mind stories with themes like this. All within the bounds of fiction ofc. Thats why there are readers for stories like this, because its a safe place for them. They can control when to stop reading, and have the choice to engage or not. Its weird yes, and not many ppl can handle stories with themes such as sexual violence but again, fandom in general have always been for the "weirdos". It all just boils down to what we can/cant handle, and choose to engage with. We all have different preferences and tolerance afterall.

i ain't a purist or whatever but genuinely HOW do people off by seeing people get raped(even if they did smth wrong) don't attack me cuz it is weird