The Canned vs. Dry Food Feud

Here are some definitions, as to what, exactly, we are feeding our cats. Feel free to add ones that you come across or have questions about. Also, feel free to be disgusted and not feed some of this stuff to your cat.

Chicken-By-Product-Meal: Chicken by-product meal consists of the ground, rendered, clean parts of the carcass of slaughtered chicken, such as necks, feet, undeveloped eggs and intestines, exclusive of feathers, except in such amounts as might occur unavoidable in good processing practice.

If cats are carnivores, does it make sense to give them food that contains, wheat, corn, soy or rice? If you knew that cats digestive tracts were too short to properly digest those grains, why would you bother feeding them this stuff? 'Cause it smells good, it's cheap and it doesn't spoil. Is it better for their teeth than canned? Surely not! More to stick to their teeth! And what about water intake? Cats crave water on dry food, supposedly to help them flush build up out of their body that dry food adds! Just doesn't make sense to me.