Agreed. Once a network becomes too homogeneous, its collective problem solving abilities go way down. Effective networks can adapt to and benefit from a large number of different fluid participants. It is a cheap way to get complexity/variety from simple individual nodes, and to be more robust, safe-guarded against variance and overfit.
The author aims to converge upon a group with a good morality (even though its members may have been in the minority). But what is to say that all-good morality is good for a group's decision making as a whole? Would it be sustainable from an energy viewpoint? Or collapse and destroy everything? Won't we need a supply of villains for our moral heros [1]? That to converge on an optimal answer as a network we need wildly opposing views? That to be stable an ecosystem needs variety, decay and destruction?
More philosophically: Is a program like this moral cooperation plan based on pay-it-forward-currency even moral in itself (as it clearly discriminates)?
Attempts at a supermorality have stunned philosophers and logicians for ages. If a rich benefactor would give a 1000 people in a room a 1000$, and if you ask for more you get 1$ more, but 999 people would get 2$ deducted, people would leave that room with some having enough to buy a cup of coffee. 1 million dollars wasted by the greedy individualistic game theory that seems to be in place in animals: I want energy for me and my family first, forget the network. Contests to give a $ amount equal to the lowest unique number send in, would have perfectly rational players roll a dice with the number of contestants, all submit 1 trillion, and the one person who rolls a 1 submits a billion. Instead they receive bids as low as single cents in a manner of days.
[1] http://www.sciencedirect.com/science/article/pii/S0022519311... "The joker effect: Cooperation driven by destructive agents"