. . . Is based on him misunderstanding what Hoid is trying to do.
He goes to see the Nightwatcher / Cultivation after Gavilar's death, understanding that something is really, REALLY going wrong.
He gets the gift of capacity, with pros/cons of intelligence and compassion.
And on the Day of the Diagram, we get this:
"But who is the wanderer, the wild piece, the one who makes no sense? I glimpse at his implications, and the world opens to me. I shy back. Impossible. Is it?"
Given what Taravangian thinks needs to be done (sacrifice most of it in order to save a few [he also refers to a "seed of humanity" in the diagram), look at what Hoid tells Dalinar:
And while I am your friend, please understand that our goals do not completely align. You must not trust yourself with me. If I have to watch this world crumble and burn to get what I need, I will do so. With tears, yes, but I would let it happen.