you can laugh off Bob Marley, but look at what he achieved and the impact he had on society... he was only 36 when he died.
by the time the Beatles broke up, George Harrison was still only 27. I'd say he realized his potential. Pot didn't kill John Lennon... Willie Nelson is still alive and touring and putting out albums at 80 years old. Maybe if Jimi Hendrix hadn't drank so much that night and instead smoked a joint he might not have choked on his puke. damn alcohol robbed him and us of his full potential.
of course those are just stoner rock musicians.
as for the Really Productive & Respected members of our society.... how many "successful" (we all have different definitions), really successful doctors, lawyers, engineers, executives, professors, writers, etc ect... how many of them are coming out to tell everyone "OH HEY BY THE WAY WHEN I COME HOME AT NIGHT I SMOKE A JOINT INSTEAD OF A GLASS OF WINE!!!"
nobody. so, again, the "name a successful stoner" game is incredibly silly.
maybe if it were more widely legal and accepted we wouldn't have a society going nuts from prescription meds and sleep aids and alcohol.