Good people do want to go into policing, but the bad people don’t want them in their gang, because decent people are a threat to their way of operating and might land them in prison.

If a group of people is too rotten, then it just perpetuates itself. People that are too smart or have too many principles, won’t even get a chance of joining. People who have started on the job will soon be presented with a moral dilemma, if they make the wrong choice, then the rotten group will start bullying them to force them out.

If it gets to the point that acab is true, then a clean start is the only fast way. Hire outside mercenaries to temporarily take over police tasks and start a new police force from scratch, with better rules, regulations and indepedent oversight. And without allowing the old cops to rejoin, unless it’s in specialized technical roles.