I think the pervasive prudishness of the past is probably the pendulous peak of a previous period of promiscuity. Simply put, an overreaction to a time similar to what we're going through now. Sex idolized and everywhere.

Sex is like fire, it's hot and powerful. Families gather around it for warmth and life. Children should be taught to respect it, but not trusted with it themselves. When its taken for granted and treated like a toy, it can burn down everything with it's consuming passion. I think the prudes of the past came from traditions of the once burned, twice shy, so to speak.

Of course, never having any fire in the home at all results in freezing, and desperately trying to find it elsewhere....