It's that way, and always has been.
I personally worked with many that were good cops basically, BUT they put self before everyone.
Had Chief (now deceased) that was an alcoholic, and loved to fish. If you went fishing with him, you go promoted. All you had to do was drink with him.
I watched these same officers get more rank, then slowly undermine him, because they all wanted his job.
An one eventually got it by drinking with him, while pointing out key city officials that the chief was a drunk.
My point in this short story is. AMBITION, will get things done.