As to your second point, not all Nash equilibria are beneficial. Gang formation is a lot like a Keynesian beauty contest in that appealing to the basest parts of our nature is the safest bet, and I think we can agree that this has nothing to do with anything good.
People do not need to "band together to survive" in that sense. Those gangs were mainly shaking down businesses in their own neighborhoods anyway, and everybody is a lot better off now that they're history.
As to your second point, not all Nash equilibria are beneficial. Gang formation is a lot like a Keynesian beauty contest in that appealing to the basest parts of our nature is the safest bet, and I think we can agree that this has nothing to do with anything good.
People do not need to "band together to survive" in that sense. Those gangs were mainly shaking down businesses in their own neighborhoods anyway, and everybody is a lot better off now that they're history.