I don't mean that it's the claim of the Nash equilibrium itself, I'm referring to the common belief that self-interest alone is a functional guiding principle.

I don't mean that it's the claim of the Nash equilibrium itself, I'm referring to the common belief that self-interest alone is a functional guiding principle. Objectivists, some libertarians, etc. I take the Nash equilibrium to mean that everyone knows everyone else's strategy and no one has individual incentive to change. But when that balance is reached, there can still exist superior choices that require coordination where the result will still yield better individual payoffs for everyone. So that's a refutation of the notion that self-interest is king. That point can always be contested by dickering with the definition of self-interest, for instance by saying it's by definition in someone's self-interest to coordinate, but that's about where the usefulness of the discussion falls apart. It really just comes down to how many externalities you want to bring in to your mental model.