Joseph Campbell is not regarded within anthropology and paleontology as a serious scholar. He is a purely pop-sci phenomenon, boosted by his association with Star Wars and friendship with Bill Moyers. Maybe not exactly a crackpot Graham Hancock kind of figure, but more comparable to that instead of anyone authoritative.
That's for the best, but I usually hear him quoted in the context of storytelling. His popularity definitely makes him relevant there, but I think he also started with real insight about hero-quest stories.
Beowulf and Episode IV – A New Hope may not have much direct bearing on any given person's pubescent path, aside from media consumption, but within it: much.
