Why were strangers the chosen demographic?

This isn't one of those posts that debates the statistical likelihoods of harm on the matter depending on your chosen variant of the scenario. Thats stupid and misses the point.

This is a post about demographics

The man v bear debate was about a stranger vs a bear in the woods which was used to raise into the public discourse that rape is still a prevalent issue.

why a stranger when most rapists aren't and not by a small margin? I mean obviously there are a variety of reasons but I never really saw much discussion or address of this fact when it was a big thing.

https://www.rainn.org/statistics/perpetrators-sexual-violence#:~:text=Perpetrators%20of%20Sexual%20Violence%20Often%20Know%20the%20Victim&text=59%25%20were%20acquaintances,were%20strangers%20to%20the%20victim