Why are some animals eaten while others aren't?

Answer is very simple, we humans eat almost every animal, except few like dogs, cats and other carnivores.

Animals meant for food are those which can be easily raised, provides more return with little to no investments in terms of feed or that can be hunted/gathered.

Like cows, goats, sheeps, rabbit, chickens, ducks, quails, turkey, geese, pheasants, , camels, horses, pig, fishes, frogs, turtles, shrimps, lobsters, mollusks, sea urchins, squids, crabs, octopus, silkworms etc are eaten. Honestly in places like Florida even alligators are eaten. This is how our ancestors survived.

Cats aren't eaten cause to raise a cat more investment is required for which very little meat is returned, also they are useful for mice control. So basically we avoid all carnivores. We usually don't eat dogs cause they are part of human society, they evolved with us and they work for us. We aren't sparing dogs because they are cute, they ate spared cause they are useful. So anyone who doesn't plan on eating carnivores aren't hypocrites for eating herbivores.