I viewed a house to buy years ago, before I had children. it was also a childminders, run by a mum and two adult daughters, so they had a lot of children. It was chaos, children were in rooms unsupervised, a baby was asleep in a downstairs bedroom (teenage boys room) with the patio doors open... I was not impressed.
I also went to collect my nephew from nursery, I stood outside watching, the nursery worker was just staring into space, while the children were trying to talk to her. The baby room had babies sleeping on gym mats. (it wasn't a cheap nursery either) The entire place was filthy.
I've also seen many a nanny or childminder ignoring children at playgroup.
There's also a childminder I see daily on walks, all her children are perfectly behaved, well mannered. She walks them a fair distance, past the animals (small farm with, pigs, horses, donkeys, chickens, sheep, ducks etc) then down to the park. Pretty smart of her, it must wipe them all out, and keeps them busy in the afternoon. Therefore good childminders do exist.. I have no idea how you find one though.