To play devil's advocate: if I were the most decent nicest cop in the world I could see why I wouldn't want my every word and action on camera. It'd severely limit things I could say in confidence to anyone, and if I were say speaking to a victim of a crime its difficult to comfort people with a camera in their face. I'd be worried to being reduced to essentially the role of a call-center employee with every interaction graded not only for not screwing up, but also adherence to rigid policy.
Its dehumanizing and eats away at the core of any intelligent person wanting to ever be a cop.
These concerns are spurious. You describe situations in which most cops, "nice" or not, would simply turn the camera off. Other situations include using the restroom or making personal phone calls. No one ever said the camera had to be on all the time; how would that even be enforced?
The camera should be on in any situation that might later be a subject of dispute. If it's off in such a situation, the courts should consider that a reason to disbelieve the cop who turned it off. A cop who doesn't possess the judgement to operate a camera, probably doesn't possess the judgement to carry a firearm either.
Well, given the mandate by some police departments to only hire the less intelligent...
I subscribe to the notion that cops absolutely need to be held to a higher standard, esp. given their potential for exponentially causing harm (because guns and LE powers).
Its dehumanizing and eats away at the core of any intelligent person wanting to ever be a cop.