This is the reason we say ACAB, at least here in the US. (Idk if they say this in the UK.) Because the good cops, the good people, just leave. The good ones know they cannot change or support the corruption of the organization to which they’ve become attached and they walk away. The ones who remain are those who are willing to sit with the atrocities of their co-workers and do and say nothing. They condone it through their silence. The good ones won’t even unite to protest the bad ones, or even speak out against the organization’s corruption. In the US the law enforcement system was corrupt from its very foundation.
It is also the reason I am not a police supporter.