I would never underestimate the influence of herb on Reggae music myself, and I've heard some funny stories about the musicians preferring certain studios because they knew it was tolerated to step outside for a smoke. IIRC Coxsone was okay with it if he didn't see it happening .
It wasn't just a Rasta thing, and some of the Rasta musicians didn't smoke while playing,especially drummers like Sly.
My personal views on Ganga are not important, but anyone who listens to Reggae owes it to themselves to listen to some heavy dub or righteous Rockers very loud after getting 'well red', at least once in their lives.
I can pretty much guarantee an 'oh, now I get it' moment. And you might not be able resist busting a skank, either.