Simply, because puritan busybodies on BOTH sides of the poltiical spectrum, were afraid, and many still are, that someone, somewhere might be having an unapproved good time.
It’s not just that: one might point out that the usual slang for sex, came from “For Unlawful Carnal Knowledge”.
One STILL sees teenagers getting arrested for “statuatory rape”, where no rape of anything but the sensibilities of someone who insisted on sticking their nose into the situation. . . .
