And "bad cops", where they exist, do not any foothold over the entire department.The fear comes only from knowing that the rest of the good cops may not be that accepting of youafter you rat someone out.
The classic sister who is a tattle-tale. You go play and avoid her because you fear she will report everything you do that may or may not be wrong.
Think of it this way... If you rat out your mom for stealing cable TV... your brother, sister, and dad will not like you for it. This does not mean they are bad nor does it mean they have any foothold over you. You know that they may no longer accept you.