The question is why our incentives are setup such that greed, exploitation, etc. are favored over other traits.

Of course we will always have some level of people doing what they think is right even if it goes against the incentives in place. A system can't be stable when it depends on that though, if we want society acting less greedy we'll only get there by changing the game rather than being angry that people are figuring out the rules already set and trying to win.