Yes, and so we should treat the result with caution. But the results I were critiquing are worse, because they assume homo economicus plus some very specific deviations, or some very specific (non-free market) environment.

The paper (and most game theory based papers) also assumes that people are perfectly rational and have perfect knowledge. The only difference is that instead of actions being restricted to the free market, and payoffs being consumption, game theory allows an arbitrary environment (chosen by the paper author) to provide the actions and payoffs.