I think we should also remember that for all the talk of certain jobs being 'careers', ultimately, they are jobs.
Have you ever had a really shitty job, along with a shitty boss, who asked you to lie about stuff? I know I have. At the time, I didn't consider the stuff I was lying about to be that important, so I went along with it for the most part. This is how it works, even within 'institutions' like the Police force, quite aside from the point that there were probably very few who knew what actually went on in comparison.
Don't misunderstand me...I've done a fair bit of whistle-blowing in the past. In retrospect, it really didn't change anything in most cases. I had a terrible boss once, who drove me to the point of desperation. For my own sanity, I left the job. A few months later, I heard that this boss was doing the same kind of stuff to one of my colleagues, and that this colleague was taking this boss to a tribunal, of sorts, over it all.
At the time that I was employed there, nobody really believed - or rather were not interested - in what I was saying this person was up to. Once I heard what had gone on, I took it upon myself to write to the people involved explaining why I had left. This boss later left of their own volition and still has a fair career, as far as I'm aware, despite their behaviour.
My point being, it's difficult to grapple with these often faceless 'entities' on your own. I can only imagine how I would have behaved, had I a family to feed and a roof to keep over their heads. What I can say for sure now though, is that I wouldn't ever go quietly again. If not for my sake, then for the sake of those I work with.
Some people see the whole, silly game for what it is and just resign themselves to it. Some people don't dare question authority and do as they're told. I'll add that those with the latter kind of personality often do better in services like the police or the armed forces for very obvious reasons. Not all people with these careers are like that, but it is something that managers and recruitment specialists might look for in prospective candidates, imo.