I agree that no one insight in this essay is especially surprising. But I think the right way to think about this is Paul Graham's framework http://www.paulgraham.com/sun.html. Paul points out that if you are talking about very general topics, even a small delta of novelty is useful.

I think that describes Ray's work here well. He is talking about a very general topic (the narrative arc of history). It's hard to say anything completely new about a topic like that, but something that is only slightly new is still valuable.