The reason cats are so pissy is they're the perfect killing machines but they weigh 8lbs and we keep picking them up and kissing them.

Did you see the season 1 finale of Sandman? It was two stories. One was an animated story about a cat who was frustrated with the fact that humans are so much bigger and dominate them in subtle ways that they don't even realize is going on. The cat goes to the Dream Lord, who tells her that in the ancient past, cats were much bigger than humans, and when they grew tired of humans petting and loving them, they would hunt them and kill them. This happened until humans dreamed a new reality where cats were little and cute. (Dreaming, in this universe, can create a new reality and alter the past as well as the future.)