I disagree about gangs not having an ideology. Though their ideology might not be obvious - not even to the gang members - it exists. Gangs have a collectivist ideology, they believe in forcing some individuals to "sacrifice" for the "greater good" of the collective. Gangs, like terrorists or immoral governments, impose their will on others by force. Morally, all are equally evil. It's only when we ignore morality and look at it strictly in terms of physical violence on a sliding scale that distinctions are drawn. Laws may accomplish a goal with less violence than physically putting a gun to someone's head but both actions are equally immoral.
esprit de corp is employed all over as a means to keep focus and motivate. and when tha fails capping the stray solves that problem. its all good so long as the cash is flowing.