I think that people who balk at the phrase "all cops are bastards" might be helped out with "good cops don't last."
Sooner or later, every cop will encounter a situation where they can be complicit or try to do something about it. A good cop will try to do something about it. They will encounter immediate resistance, and will be pressured to shut up and be complicit (whereupon they cease to be a good cop). If they persist, they can expect to be fired, harassed, thrown in a mental hospital, or even directly physically attacked and murdered.
Hell, if they're in the NYPD, after they're done with you they'll probably make a commemorative challenge coin about it.
All cops are bastards because good cops don't last. You are absolutely not allowed to be a good cop.