There's a gif that humorously demonstrates this mentality [1] and shows a police officer instinctively pepper spraying the air around him in response to falling down, even though there's no one around him.
Personally, I blame the laws & culture that encourage excessive civilian gun ownership. The common excuse for preemptive police brutality is the fear that a civilian could be reaching for a gun which puts the officer's life in danger. Without guns, police have no excuse to strike preemptively and it'd be much easier to gain political support for de-arming the police.
The moment Seattle organizes an "autonomous zone", they appoint a violent warlord with a Kalashnikov and proceed to shake down local businesses for funding. If you don't need the police, why the warlord? If you don't need capitalism, why the shakedowns and requests for, I quote, "soy products"?
https://www.reddit.com/r/CapHillAutonomousZone/comments/h0lo...
US citizens deserve the same response in daily life from a police under the "serve and protect" banner that an enemy combatant gets from the opposing military during an active conflict? You can't treat every citizen as if they are the worst possible one. If you got this "you could be the worst ever" treatment in any other situation you would certainly not find acceptable to reference the fact that the army also does it while in a war.