All but the Cat actually has a use.
If you were an ancient farmer or sailor who's stored food was being depleted by rodents you might think different.
i must respectfully disagree. i live out in the country and my mother lives blocks away from the local butcher shop. cats can be wonderful tools to keep the local rodent population down. sadly, they can also bring home trophies of headless cottontails (who usually are great at wiping out one's vegetable garden or fall display garden)!
My husband had the same attitude about cats until one day all our cats were gone. We store 2 tons of grain at a time to feed our horses. It didn't take long for the place to get overrun with mice. So we went out and got some cats. He's actually finally taken a liking to some of the cats.
Cats aren't domesticated; they decided to live with people because we attract good things to eat, like mice. Of course, we've completely misunderstood this and now feed them directly, but that's OK with the cats, too.
With dogs you get devotion; with cats you get mutual utility and, possibly, friendship between equals.
The cat has the best use in decimating vermin populations that not only deplete food supplies, but carry diseases.