Huh. My impression from a distance was that "rape culture" was partly two things that had been going on to similar extents for a while previously: a form of motivated commonly accepted carelessness around intoxicants and consent, plus occasional clusters of men in that scene who would engage in darker things and support each other in doing so. This was amplified to a social construction "rape culture" by a moral panic, associated with changes in the surrounding culture and feedback effects through the power of social media, that worked through increasing the power of side-taking social actions against anyone who didn't themselves side with a higher standard (a standard that was so much higher than the previous practice as to be unreasonable, since it would predictably be taken literally). The allegations against Brett Kavanaugh are about his alleged conduct in the early '80s, and the way people act about those allegations suggest that they were not particularly unheard-of at the time. Also the internet didn't get that popular until the late '90s.