It's not relevant to my argument. The point was that in some cases, individualism can be efficient. A didactic example is meant to be recognized as such and not attacked for technicalities in its formulation; rigor was not here the goal. Note, for example, the use of "maybe". But congratulations for irrelevant nitpicking, I guess.
Sorry about that. I thought the "maybe" was sarcastic.
Anyway, the parent's point seems to be that individualism is a strategy that is optimal for a single person, but suboptimal for society. The reason is that what activity maximizes your financial return does not generally maximize the return for society as a whole. Individualism is therefore not optimal. A specific example would be a world that had no crime and therefore no need for security, law enforcement etc. Obviously a lot more efficient than a world with crime. However, since stealing would be free of consequence, individualism dictates that you should steal in this hypothetical world. Everything may not be a prisoner's dilemma, but most is. I don't see how that's nitpicking.
