Marley's ex-bandmate, Peter Tosh, used to complain about this. Wikipedia says: "Tosh became bitter about the success of his ex-bandmate, at one point claiming that the only reason Marley was so successful was that his father was white ..."
Sorry, Peter, but I think the real reason was because Bob wrote better tunes than you did.
I remember walking out of a Tosh show at the Roxy in the late 1970s, and the club put on the English group 10cc's pop reggae hit "Dreadlock Holiday," [Youtube] and thinking to myself, "I know Tosh is supposed to be Mr. Authentic Roots Rock Reggae and all that, but this piece of fluff is catchier than anything in his whole show."