Folk = World, Reggae = World, therefore Folk = Reggae, nonsense of course, but I think something like that may be happening. And I quite agree that 'folk' has issues but that there's no better term for much of what goes in that bag, much less all of it (which raises the question of whether it all belongs together).....roots, rock reggae! as they used to say.
My LPs are generally not in categories (except tribute albums), my CDs are, both decesions space driven.