You make a lot of broad generalizations which are open to correction.
For example, the "counter culture" phenomenon was not in the 50s, but a decade later.
Your explanation for the revival of hat wearing in the 90s is patently inadequate.
"The mens' shag styles of the 70's and super-coiffed, mullets and poofy hot combings of the 80's simply could not survive the wearing of a hat. By the 90's, men were back to tight trimmings and regular cuts and hats began to sneak...