It's the underlying prudishness at various layers (some of it is only historical, some of it lives in the present to varying degrees in various sub-populations

It's the underlying prudishness at various layers (some of it is only historical, some of it lives in the present to varying degrees in various sub-populations) which makes the rebellious "Sex, Drugs, and Rock & Roll" thing a thing at all. If there was no prudishness in the first place, there would be no space for it to be popular to revolt against it.