In this life, you are rewarded for not having integrity, compassion, empathy etc.
If you defend your underlings (and the broader population they are supposed to serve – pupils, prisoners etc) against some stupid and damaging scheme that your boss has proposed, then your boss will say (or think) “You are not a ‘team player’ [obedient], and you are giving me problems instead of solutions. I am not going to promote you. Your days here are numbered.” While smiling at you and saying “that’s a very good point.”
So, say you want to get ahead; you swallow your pride/integrity/compassion. You screw people over. And promise yourself it’s a one-off, that you won’t do it again. You get a promotion. You have been rewarded for having cauterised your decency. And what is rewarded is repeated.
You have learnt that it is possible to do shitty things, and the broader organisation will generally protect you in doing them.
And your new boss, who has seen that you are willing to cut corners to “get the job done” etc, gives you a bigger version of the same dilemma – protect your team or yourself. And now you have a new status, and perhaps a new mortgage, to protect. And no-one (not even yourself) expects you to buck the system, because you haven’t thus far. So you say “yes” and you go to your new underlings and tell them they have to implement your boss’s crazy plan. And if they defend their underlings (or the broader population they are supposed to serve) then you will say (or think) “You are not a team player….”
Before anyone has time to blink, there are entire tiers of management made up of the incompetent (see the Peter Principle and the Dilbert Principle) and the amoral….