A lot of folk/pysch has enjoyed a renaissance long after the 60s.....Rodriguez, Linda Perhacs, Bill Fay, Anne Briggs, Vashti Bunyan.....and all of them are still alive.
Mercifully in Nick's case, he didn't make a bad record (31 almost perfect songs) and, for whatever reasons, got out just as the industry might have foisted awful production on his records. A Nick Drake record in 1983, no thanks!
He also had a very sympathetic record label (Island).
Death helps the mystique for many (unfortunately); but I think fantastic songs, wonderful production and beautiful LP sleeves matter more.
I, for one, would revere these three LPs if he was still alive. I revere the Incredible String Band's LPs and they're both still with us.