Dogs are stupid, loud, and smelly.
Cats are smart, quiet, and can clean themselves.
I've owned many cats, and they have all been loving and affectionate, but also content to do their own thing if you're busy. Conversely, I am currently taking care of my brother's dog while he is out of town, and the stupid thing constantly tries to bite my feet, will not leave me alone, and will whine for hours if you gate him in the kitchen and try to ignore him. I've never understood animal cruelty, but I seriously think I could bludgeon this stupid dog to death and not feel a thing, except maybe joy at finally having some peace.
I may have covered this, but I hate dogs.