You've made me laugh here. Yeah, the article isn't about economics. It's about how psychopathic the EIC was. So we can dispense with the strawman about robber barons, right?

Now it's my burden to speculate that early economists' models of so-called rationality might have gotten tangled up in the observation that powerful economic agents have psychopathic tendencies.

How difficult do you think it is to make my case? What's funny is that directly after you dismiss the argument for being "terrible," you start to make my case for me in your last paragraph. All you need to add to your version is that psychopathy isn't distributed randomly in social positions. There are kinds of psychopathy that are liable to take you straight to prison (criminal psychopathy), and there are subcriminal kinds that can boost your career. There are also learned, virtual kinds you can acquire once you've attained a powerful position in society (because power is liable to corrupt your character).

So economists will indeed have observed how capitalism works. They'll have noticed, for instance, what the EIC tended to do. And they'll have wanted their model of the "ideal" rational agent to reflect the essence of how wealth and power work in modern, secular settings.

If capitalism is dominated by relatively inhuman actors (because all societies are dominated by corrupted individuals), but economists think modern societies are governed by reason rather than God, they need their model of reason to apologize, in effect, for the psychopathy that naturally prevails. Hence their celebration of, or emphasis on, instrumental, strategic reasoning. (I have another article coming out on this, too, by the way.)

Indeed, my argument was never so complicated here because it's pretty obvious what happened with the model of Homo economicus.