This is an interesting article, but The Tragedy of the Commons is only 1 of 7 Nash Equilibrium possible. It was cherry picked for a funny thought experiment where Joker is the good guy. Now let's try the Volunteer's Dilemma.
In the Volunteer's Dilemma a group is faced with an inevitable negative, and the only way prevent it is for one member to assume the negative unto himself. The classic example is jumping on the grenade. Nobody wants to do it, but somebody has to or everyone dies.
1) Assume Cooperators and Defectors only. Cooperators will eventually volunteer, Defectors never will. There can be a balance where Cooperators significantly outnumber Defectors, but if this balance is disturbed the population will eventually end.
2) Add Jokers. Jokers in this case would be like Defectors and never volunteer. Worse, however, is that Jokers would probably be so interested in the destruction that they would actively prevent volunteering. There can be no balance in a group with even one Joker still alive, and the population will end.
3) Add Batmen. Batmen neutralize the Jokers' ability to prevent volunteers, and are willing to volunteer themselves. The balance is restored as long as there are enough of these individuals to restore moral and put the group first.
So now in my thought experiment, Jokers are harbingers of the end while Batmen are necessary for survival.