I used to think about this a lot. Burroughs pretty much founded American drug inluenced prose, and the counter-culture. Now they are all dead. Him, Leary, Kerouac, Ginsberg, Bukowski, H.S. Thompson, Abbie Hoffman,and Jerry Rubin.
Noam Chomsky and Howard Zinn are still alive and kicking, even, though, they are about the same age, and for lack of a better word, as left, as most of those listed above.
Why do you think that is?