I would imagine this happens by itself really: once something like corruption/bullying/sadism becomes established enough in any small or large institution, it t

I would imagine this happens by itself really: once something like corruption/bullying/sadism becomes established enough in any small or large institution, it tends to drive people with a conscience away (instead of attracting them to where they are most desperately needed) - where that doesn't happen actively, that is, as a sort of self-defense against likely snitches. So over time, left unchecked, it just compounds.