An injust policy is not a good policy by definition. There is a reason "better a hundred guilty go free than one innocent should suffer" is an axiom. To do otherwise utterly fucks with incentives and promotes selfishness in the worst of ways. Why bother being honest if it is no protection? Do whatever the fuck you can get away with and maximize the personal advantage. That is a recipe for breakdown. Injustice has a way of creating a "karmic backlash" of reputations which is less than precise. Not through any cosmic force but that in a world with billions of agents actions begetting reactions. It goes beyond classic vigilantism and into reputations in general. Letting the Mai Lai Massacre go unpunished certainly contributed to Vietnam Veterans branded baby-killers.

On another note I highly suspect residual trauma is a reason for teachers having issues with parents, and schools with willingness to fund. The tree remembers and assumes the worst of teachers based upon their own experience.