Come on man, you're joking, right? He certainly didn't chart like Elvis but he's not known "because of the hippy culture San Francisco thing". He's mostly known because he was odds on the greatest electric rock guitar player who ever lived. It's not just opinion, it's shared by many of his peers.
Rolling Stone's "100 Greatest Guitarists: David Fricke's Picks" - #1 Jimi Hendrix.
From another article in "Classic Rock" magazine:
ERIC CLAPTON: He definitely pulled the rug out from under Cream. I told people like Pete Townshend about him and we’d go and see him.
PETE TOWNSHEND: The thing that really stunned Eric and me was the way he took what we did and made it better. And I really started to try to play. I thought I’d never, ever be as great as he is, but there’s certainly no reason now why I shouldn’t try. In fact, I remember saying to Eric, “I’m going to play him off the stage one day.” But what Eric did was even more peculiar. He said, “Well, I’m going to pretend that I am Jimi Hendrix!”
BRIAN MAY: I’d heard the solo on Stone Free and refused to believe that someone could actually play this. It had to be some kind of studio trickery, the way he talks to the guitar and the guitar talks back to him. I was already playing in a band called Smile and I thought I was a reasonably good guitarist, so I knew it wasn’t possible. So I went to the Saville, determined to be a disbeliever, but I was swept off my feet. I thought, “This guy is the most astounding thing I’ve ever seen.” And he did the Stone Free solo live, absolutely perfectly. It was back to the drawing board for me.
JEFF BECK: For me, the first shockwave was Jimi Hendrix. That was the major thing that shook everybody up. Even though we’d all established ourselves as fairly safe in the guitar field, he came along and reset all of the rules in one evening. Next thing you know, Eric was moving ahead with Cream, and it was kicking off in big chunks.
JOE SATRIANI: Red House was a nod to his blues roots. I think the most underrated part of his playing is his sense of melody in everything he played, his way-in-the-pocket rhythm playing, and his combining of both into memorable parts that defined each song as a unique piece of music.
LESLIE WEST (guitarist, Mountain): I heard Hendrix playing Are You Experienced and I said, “What the fuck is this?” It blew my mind! The way he used that whammy bar? Forget about it. He’d knock those strings out of tune and then he’d stretch them right back into tune. The guy was unreal.
JOE BONAMASSA: I don’t think there’s any music that you hear on the radio today that would be possible without Jimi Hendrix.
STEVIE RAY VAUGHAN: I loved Jimi a lot. He was so much more than just a blues guitarist. He could do anything.
JIMI HENDRIX: I’ve been imitated so well I’ve heard people copy my mistakes.
