Businessmen forming a cartel are also in a PD situation. Do we want businessmen to gang up against their customers?

It probably depends on how you frame the game -- are businessmen the only players, or are their customers players too? In this model, only players have utilons, there are no utilons for the "environment". Or perhaps the well-being of general population could also be a part of businessman's utility function.

If customers are not players, and their well-being does not affect businessmen's utility function (in other words, we talk about psychopathic businessmen), then it is a classical PD.

But it is good to note than in reality "warm fuzzy feelings" are part of the human utility function, whether the model acknowledges it or not, so some our intuitions may be wrong.