The day we bury the last decrepid flower child will be the day the air gets fresher in America. What a pampered bunch of weirdos, coddled by their clueless parents and never asked to grow up! Drugs made them feel important, and obviously caused the brain damage that still makes them feel that way.
I agree, I think he realized that the remnants of the Beat generation, and I think he belonged there more than in the flower child /hippy category, were all dead and gone. Since most had gone out in a tantrum, he followed suit.
The realization that the children had lost and the adults were again taking charge of the culture was just too much.