Just two comments:
I spent 17 years (not in the area of dementia, patient care or care homes) campaigning for people who were getting the short end of the stick. In a word, those people were grateful to me, and those I blew the whistle on were not. To conclude, I was extremely well informed, trained in justice and equality, my psy degree specialised in moral competence..... so I exposed them well. Net result: I got post-traumatic stress disorder, ended up on anti-depressants, had to leave Ireland for a new country. People in power who abuse their power are not about to be exposed.
Shouting/petty neglect as an individual is another matter. Again I write this comment based on my experience. I have shouted at Mum (with moderate Alzheimers at the time). Why? Because I was faced with bizarre, abnormal behaviour - I didn't like what I saw in a person I loved very much, so denial of her dementia set in, and I tried to handle my distress by 'treating' her like a normal person. If she doesn't hear, repeat. If she won't listen, speak louder or shout. Not very elegant, elevated or morally competent, but there you have it. I found her absurd behaviour and thoughts very upsetting, so down came my mental hatches, out the window went compassion and good sense, and my animal brain clicked in: I'm not having any of this nonsense. Needless to say this tactic doesn't work.
I know these comments are a bit off track, but the thread is thought provoking.