Except people tend to solve the prisoner's dilemma problem well enough that many research experiments lead to cooperative strategies. So it's a poor model of the real world. It's a dilemma for people who believe everyone's a rational optimizer.. for lack of a better word let's call them economists. There are variations of coordination problems that are actually complex enough to go unsolved in the real world and in some cases they don't even necessarily require irrational decisions, they just require a large amount of coordination to adjust the state to something where each individual decision has justified payoff.