Like most (all?) big counter-culture movements, most of the people who were “in” it were not really there for deep seated beliefs. It was cool, there were parties and music, sex and drugs were plentiful. Then it was time to grow up put all that stuff behind them.

I don’t mean to disparage the whole hippie thing. Lots of people really believed in it and do to this day. I just think the majority were there for the fun then got back to “real life”.