Because a cat is a loving cat.
Cats are not capable of higher thought.
It is still sad though. A cat just like a dog would be considered a "common house-pet" and thus should be treated like one, not fed to snakes.
I can see where you are coming from but in all honesty I think you have to realize that animals have feelings and are much more capable of understanding and holding a pure heart. Humans on the other hand seem to think that they are just some handicapped animal and they do not care about stuff.
My question is and I want anyone that was being a richard laughing at this to think about it this way. Could YOU of sat there and fed that helpless cat to a snake and not feel any emotion whatsoever? If you think you could of you are probably lying because you have never had such an experience. Set aside you also probably would say you could because you think that is what will make you look "cool/hip/blending in with the modern moronic style". It makes you look like a selfish idiotic moron who has no feelings.
Anyways I think that the whole thing was an obvious religious affect on worshiping an idle such as a snake and using the classic sacrifice a living to keep the spirit of the gods alive thing.. Whole thing is still sick and wrong.