Cats are evil.
Of all the cats I've known almost all have been good-natured, probably a better percentage than the dogs I have known. The only mean cat I've known was unfortunate as a kitten to meet up with a maladjusted punk who succeeded in producing a cat as unlikable as himself.
Cats are DIFFERENT. Not evil. Dogs are slavish and sycophantic (and I love ‘em for it!) and cats are more equal cohabitors.
They are also art critics which make them worse. "Mew doin it wrong"