He helped open the floodgates to sexuality as a public topic. By making it public, it gave way for us to express ourselves without being smacked over the head too much, which then led to proper sex education. Sometimes I wish our forefathers had the knowledge that it probably wasn't a good idea to literally screw like rabbits without the proper preparations or the consequences for being too "promiscuous".
We'd probably still have John Holmes today.
Of course he didn't do it overnight, in the 60's one of the raunchiest songs you could hear was "I wanna hold your hand", and John Lennon thought he was feeling like a modern day rapper when he says "gland" instead of "hand".
It's not about his sexuality for me, its about sex as a whole.
I think you're giving him, the individual, too much credit. He did what he did for profit. The end result might have been a rethinking of sex but that was incidental.
Still, I can understand remembering the man's younger libido and what it did for the country but he grew into a letcher that thought it was okay for an 80+-year-old to pursue teenagers. I'm far right of an SJW but that's wrong. The gay community all but erased Harry Hay from our histories for doing the same thing with men. In fact, the last article I read about it was titled "The Trouble With Harry Hay" which was what place he should have in our narrative given who he became at the end of his life.