I wasn't around in the 60s, but the cynic in me suspects that even within hippie circles the 80/20 rule was still in effect in the dating game. Because the same thing is happening today within progressive/SJW circles - the "male feminist" types tend to proceed directly to the friendzone, regardless of the claimed preferences of progressive women.
The culture permeates every level. The "alpha male" culture benefited most men in 2015-2016, even if they didn't capitalize on pointless sex. The free love movement expanded it's own movement into most parts of the culture. These patterns aren't 'optional forces' that only the rich have enough spare time to participate in.
The culture force of elitism is the current phase and idolizing the rich is eternal in america.
There's a bigger picture than the current myth.
The Pareto principle pops up in so many places, I don't think you can justify an arbitrary interpretation about harems and alphas on top of the principle. We don't know why the power law keeps popping up in earthquakes, mass of stars, size of trees in a forest and a whole slew of natural phenomena. When we finally understand what natural force is shaping these distributions, it'll stop being a nice fairy story which contributes to other stories.