It was the Paris Hilton tape that started this nonsense
Thing is, no one cared about Paris. And Kim K, who used to hang with Paris, was elevated above her.
And all the the women who have done the sextape thing after, seem to reference that.
Sure, Paris started the whole "socialite sextape" thing. But, it is Kim K who people pay attention to. I believe it's because people find her physically more attractive than Paris.