It is absolutely possible to provide a degree privacy and dignity to someone who is doubly incontinent. I spent many months doing so for my dad.
I am sure he would very much have preferred not to have his adult daughter dealing with his shit at all. But given that wasn't possible, I still had the option, which I took, of doing so in the least intrusive and embarrassing way possible, given the nature of his needs. His right to as much dignity and privacy as could be afforded was one of my absolute priorities. He was a full human who happened to have a horrible and devastating illness. I thought of him and treated him as such, always, and expected others to do the same.
There are manifold possibilities in between 'leace someone to sit in their shit" and "involve as many people as you feel like in their intimate care". Can you honeatly not understand that consideration needs to be given to that?
Again, I am entirely open to the fact that it may be necessary to involve four people in OP's dad's intimate care - so is she. And OF COURSE staff have a right not to suffer injury and indignity during their work - I would never question that. If it's necessary it's necessary.
But OP is surprised it's necessary, and she knows her own father, and his illness - she was his carer for years.
Not all people who have dementia immediately descend into unpredictable violence. There is a full spectrum of responses.
Again, OP is clearly shocked at the fact that her dad now needs this cafe, based on her years of experience of him. If there has been a sudden, drastic deterioration in his ability to cope, why should she just shrug and accept that, without asking why?
And why do you believe that your opinion of the care he needs, based on never having met or seen him, is more valid than hers, based on her years of experience?
Again, do you believe it is impossible to abuse the elderly, or that this never happens?