If the police have an image problem then perhaps they need to promote a culture of restraint, civility, and justice by enforcing the law against their own at all times not just when the criminals behavior makes it onto television and sparks riots that threatens to burn down the nation.
> Somehow we lost all perspective and have come to expect that our officers, whose jobs regularly confront them with mortal danger and the darkest parts of human nature, will always display the same perfect virtues we carefully signal everyday on Facebook.
We can work on the them becoming paragons of virtue after they stop executing citizens in the street, attacking people peacefully protesting, planting drugs on people, and raping them.
https://www.cnn.com/2019/07/11/us/florida-deputy-arrested-pl...
https://www.thedailybeast.com/pennsylvania-police-officer-ch...
After we get we stop raping, framing, and murdering people yes I do in fact expect those charged with serving law and order to deal with bad people without themselves becoming bad people. People in most of the developed world seem to be managing this so I don't agree that it is an impossible dream.
Many people expressed and believed that automotive fatalities were just an inevitable consequence of the the mode of transport while others insisted on pushing for systematic reforms that drastically reduced fatalities.
https://www.nytimes.com/2015/11/27/automobiles/50-years-ago-...
Similarly you argue that bad behavior by some police is inevitable. I don't agree
Police officers in the US face 12.9 fatalities per 100,000 workers. In comparison, construction workers see 14.3, agricultural workers see 17.7, farmers and ranchers around 24 and truck drivers 26.9.
As for the rest of your argument, if the 'fine' police officers don't do anything to stand up to the bad police officers or adhere to the blue wall of silence: Then they are not fine people.
I can understand how it might feel scary, though. Just because they don't have much worse outcomes than the average American of their demographic doesn't mean that they don't have more terrifying experiences than average. That's not an excuse, though. Abusive parents are often reacting to past trauma that was inflicted on them, but we still shouldn't allow them to abuse their children. Protecting the public in a constitutional way needs to be the top priority. Officer safety and wellbeing come close behind, but they should still always be in second place.
I don't know about you but I don't have to "carefully" display not killing people who are on the ground unarmed. You're depicting people with 6 months of training as if they were in a fucking warzone every day.