No, they are not.
Because if they were, they would be fighting nail and tooth to get the 0.01% off the force and behind bars, where they belong.
As things are, there are three kinds of cops: 1. Dirty 2. Complicit 3. On the way out
You've just demonstrated that "for every complex problem there is an answer that is clear, simple and wrong." Cynicism without realism is not productive.
1) Changing entrenched bureaucracies is hard and takes time no matter how good a person you are.
2) Most dirty cops are unlikely to announce their corruption.
3) Innocent until proven guilty applies to cops also and that makes obtaining convictions hard.
Yes, there are corrupt and complicit cops who need to be brought down. But there are good ones that will act to clean up the police force where they can. Those good cops are limited by law in what they can do to reduce corruption just as they are limited in how they can deal with any other crime. This is as it should be; we have rights for a reason.