Maybe I'm an outlier, but I'm 35, have been into playing guitar/music for 20+ yrs, was even employed for music, and couldn't name a single Bob Marley tune. I'm sure I'm familiar with them if you pointed them out to me, but I've never intentionally searched out a Marley tune in my life. That's anecdotal and means nothing as to his place in history, btw. But I will say that his music is fairly recent in the scope of human history, and it might be a little early to be talking about his lasting influence. Sure there probably aren't many kids in 3rd world countries jamming to Bach & Beethoven, but their music is still taught, sold, and studied all over the world a couple hundred years later. It's influence is undeniable simply for the fact that it's still around. If people are still enjoying Marley to that level 200+ yrs from now, then that's awesome and solidifies his place in history.