People have or are supposed to have the ability to rationalize and make decisions. We are supposed to have the ability to help those less fortunate. I know many people don't make good decisions and go through life in a very self centered way but not everyone. I am not making a value decision about human life versus other animals just observations. Cats don't rationalize they are ruled completely by instinct and without being altered the instinct to reproduce is very strong. Cats are a small carnivore that was native to a desert environment which means they have a very high reproduction rate. That high reproduction rate is how they survived as a species in a harsh environment. A feral colony in many areas will get very large very quickly.