Based on the first five minutes, the whole point of his lecture is that stories, explicitly including but not limited to those framed as good vs. evil, are often dangerous oversimplifications.
I'm telling you, as someone who has read quite a lot by Tyler Cowen, that he is not as naive about good and evil as you seem to think. You've read too much into the one sentence you've quoted.
Tyler Cowen argues in a TED talk (~15 min) that stories pervade our mental lives. He thinks they are a major source of cognitive biases and, on the margin, we should be more suspicious of them - especially simple stories. Here's an interesting quote about the meta-level: