You define good as police officers willing to suffer attacks by minorities members without taking self defense steps?
Yes, that is exactly how I define a good police officer.
A police officer has a duty, and has taken an oath, to serve and protect. We train them, we pay them, and they do a job. Part of that job involves a certain amount of risk. If you aren't willing to take that risk, then you should do some other job.
Of course, a police officer has a right (and a duty) to use violence, even deadly violence in cases where it is absolutely necessary to do so to prevent imminent harm to himself or to others. The key phrase here is "absolutely necessary".
These countless cases of police officers shooting unarmed teenagers, doesn't even come close this standard.
Police officers should be held to a very high standard. They are held to a much greater standard than average citizens in the community. Part of this standard means that they should act with professionalism and restraint in all circumstances. If they feel that this puts them at greater risk, then so be it.
That's what the job entails. Let's fire the bad cops and hire police officers who are willing to do their job correctly in spite of the risk.