What you are assuming is that stressed-out, over-worked, under-paid people can still care and operate at their highest level of humanity.
Highest level of humanity? Not taunting a bedridden patient with dementia to make a video to post for likes on the internet requires your Highest levels of humanity? Fuck, I'd consider that the lowest levels of humanity.
They weren't accused of not bringing her food or finding ways to comfort her, they are accused of actively harassing a patient. That takes EXTRA effort on their part to be complete assholes, not less effort.
I'm with you on CNA's being overworked (and most staff) and I agree that owners and operators of nursing homes are greedy and cheap, but this is not about someone not "being able to operate at their highest levels or humanity" this is about people being scumbags.
But still, I agree that nursing homes are stricken with apathy top to bottom and it's a crime against old people.