Were you alive and listening to rock music during the 60s and 70s? I was, and I can tell you that there was no greater influence on the genre than Jimi Hendrix.
The man literally invented heavy metal, psychedelic rock, hard rock, speed metal, grunge, etc. He was (and to this very day, still is) one of the most unique musicians to ever enjoy Top 40 status.
His facility with the electric guitar was unparalleled. His guitar technique spawned generations of players who've followed in his style. Even forty years after his death, his mastery of the instrument remains unrivaled, and he is still revered among musicians of all stripes.
His career may have been short, but in his time, he was perhaps the most prolific musician of his stature. Most recording artists don't do half as much, in twice the time that Hendrix did.
If you're only familiar with the few hits of his that are played by Classic Rock stations, do yourself a favor and search Hendrix on YouTube to get a listen to some of his other work. Any of the cuts off the live album, "Band of Gypsies" will give you a greater appreciation for the depth and breadth of the man's incredible gift.
Not only was I alive, but I know the decade of the 60s. And The Beatles were 1964, the British Invasion followed 64-65. That included the Yardbirds. The Kinks. The Who followed. Hendrix was basically 67-70. A bio of Hendrix itself said HE was influenced by Sgt Peppers . .
My point was much of this was already in play by the time Hendrix appeared on the scene . . . . Im not saying he didnt have sway, Im disputing his No. 1 ranking.
Not stating this to diminish Hendrix, but there's another guitarist who most here would probably never put on a ‘top guitarists’ list, but who truly deserves mention - Terry Kath of Chicago. He had a lot of jazz and blues in him, and Hendrix thought Kath was great. He died young (gun cleaning accident was reported). He was very creative. Chicago doesn't top my list of the genre's of music I listen to, but Kath was superb.