It is one thing to say that you are not convinced by his arguments, but it’s pretty clear that he directly questions our conception of financial markets, markets more broadly, and our definition of “economy” that are key components of capitalism.
In fact, he challenges it so directly that you confuse his intentional materialist characterization of finance as a misunderstanding. Mostly, I think this is a result of our ideology being so pervasive under capitalism that we are accustomed to describing our artificial economic structures as borderline laws of physics. Graeber here is simply trying to insert a wedge into that line of thinking, not propose an entire alternative socioeconomic process.
It’s a bug report, not a pull request.