I think that's exactly what humans love about cats. They really have personalities. Unlike any other domesticated animal, cats aren't tasked with any job. One often thinks about mousing cats, but that turns out to have much less historical evidence than humans just... loving cats! Having pet cats and human civilization appear to be essentially the same thing. The book "The Lion in the Living Room" is excellent if you're interested in this topic, and talks about P-22 at length. Even if you're not a cat person, it's a must read for LA residents or anyone interested in anthropology.
My cat Cleo is dramatically different than Bea, and she is also magnificent!