The folks at DU couldn't have said it any better.
You’re just giving Hefner far more credit than he is due.
He didn’t invent the birth control pill. He didn’t invent the transportation systems that made living around large cities convenient where you could act with anonymity. He didn’t invent the electric typewriter and Gregg’s shorthand bringing legions of women in the office.
And all those had a much more colossal impact on the ‘sexual revolution’ of the 50’s through the 70’s than a magazine that never exceeded a few million subs. Despite whatever Hefner and some bible thumpers would like people to believe.