I deplore police militarization, but it is a logical consequence of allowing an increasingly armed public. I also deplore the "take no prisoners" attitude evidenced in some police interactions with the public, in which an alarmed and hyper-vigilant officer shoots before real risk can be ascertained, or when a citizen's behavior would respond more readily to an approach sensitive to mental health concerns. This too, however, can be seen as a result of having a heavily armed populace.
I think police have a reasonable right to expect that they will be more adequately armed than they people they may need to arrest, or otherwise interact with. This is a privilege we afford them as part of the social contract, wherein we give up some of our individual power for the sake of a broader general good. In some societies (real or imagined), a simple baton or a bowie knife, in the hands of an officer, would be enough to ensure physical superiority if things turn south. In a society like ours with its proliferation of guns, though, such superiority cannot be assumed--unless (as is actually happening) police become increasingly militarized, both in weaponry and approach.
We are destined to see a continual ramping up of aggressiveness and force from police as long as they need to contend with increasing levels of risk. It is also not surprising that the underlying judgments about danger that are brought to light by these hyper-vigilant responses will reflect the various forms of prejudice and racism that live in society on conscious and unconscious levels. The effect of this is circular. Mistrust of police can then lead to scenarios in which police feel more threatened. So the story continues. We are in a mess, but we have done plenty to allow ourselves to get there.