Why were rock artists of the 60s and 70s so fascinated by Aleister Crowley?

For instance, the members of Led Zeppelin bought houses and other items that used to belong to Crowley, Ozzy Osbourne wrote a song about "Mr. Crowley" , he's one of the faces on the beatles album Sgt. Pepper's lonely heart club band, Jimmy Page and Keith Richards contributed music to a film about him etc. What brought upon the interest of all these musicians in Crowley?