Everyone knows that cats control human thought.
This is the obvious reason for human activities toward cats: building fine sand boxes which are meticulously cleaned of dung and pee; brushing elusive fine hairs which will be lodged in human nostrils; buying expensive cat toys that will be discarded after 120 seconds; tending on to every possible cat need without any contemplation of own´s safety (have you ever brushed a cat´s teeth?).
There is absolutely no retribution: neither economic, nor emotional (cats do not even recognize their humans), nor physical. In other words, a cat is like an everlasting teenager.
And when this dominance is mixed with creative activity, the product is a cat. This was proven after viewing some graffiti in Bogotá.