I read a bio of Zappa a couple of years ago: he completely trashed the Hippie movement, probably more than the Vietnam war. He never did drugs, and was a ruthless taskmaster for those (un)fortunate enough to play for him. He staunchly opposed any censorship in music.
Frank was a real libertarian who sought out child prodigies for his band. I think he had Brit Eddie Jobson in his group at a young young age. Eddie then went to Roxy Music as violinist and keyboard player.
Robert Fripp in king Crimson was another task master.