Had cats all my life, never a dog. You have to tell dogs what to do all day...and I think that's the problem with non cat people, they don't do what they are told. To my parents, dogs were tools, not pets, you used them at work, and left them at work. We could hear our father whistle us home from a long way off...my mother couldn't whistle that loud, she had a tin shepards whistle. They didn't hate dogs, just didn't see them as pets.
We've only used litter trays for training, our cats are out door cats, and come and go as they please. To a previous reply - no, cats don't work together normally, they are loners, and have a territory to be defended at all times, sharing that territory with another cat goes against instinct. They are also not with you because of the food, although it's very handy - move a mile down the road, and the cat will go back to it's territory and starve rather than be with you.