That is the right of the voters. The police (and certainly not the police unions!) do not have any power in a republican society to override that.
It is certainly true that the way that Seattle police (and SF police, and NYC police, and NJ police, and...) want to maintain public order is different from the way that the voters want to maintain public order. But that is the very problem at hand - as the comment above says: 'current police culture basically says "Let me do my job however I want, without consequences, or I just won't do my job"'.
Police overpolicing because they don't want to do their jobs as they're told is not very different from police underpolicing because they don't want to do their jobs as they're told.
If the people want to vote for such politicians who want to vote for such judges who make such rulings, that's the people's right, is it not?
Collecting evidence is the primary responsibility of the police, and prosecutors declining to prosecute a criminal for lack of evidence is a failing of the police, not the prosecutor. Unfortunately, given the abundance of evidence against criminal cops, they still don't prosecute them, so maybe the culpability is shared to some degree.
https://komonews.com/news/local/seattle-officers-used-excess...
That is a vast overgeneralization. Check out how many extreme repeat offenders are immediately released without punishment:
https://youtu.be/bpAi70WWBlw?t=496
Seattle Police officers are literally reduced to _bribing criminals with candy_: https://youtu.be/bpAi70WWBlw?t=865