Why don't we use the animals 100% in Harvest Moon?

At least in the games I've played so far. Sure there are chicken, cows and sheep, but we can only take the eggs, milk the cows or sheer the sheep. Dear Marvelous Entertainment, it's also possible to milk the sheep and have sheep cheese! And why do we have to be vegetarians in the game? Ok, we do eat fish, but may people think also vegetarians do anyway. By the way, I'm sort of a vegetarian myself. Back to the point. Imagine taking care of your cow for so long, and then you can go to her with your axe and have a steak for lunch. Or go to your sheep. Or have a chicken soup that would cure colds. Horses are also edible, but there should be a way to get a new one then. And in the Chinese version you should be able to eat the dog too.
Or maybe instead of just going with the axe to the animal, on the DS we could use the touch glove and we'd have to follow a line, something like during sheering, to get the best meat of the animal.

Somehow I feel we won't see any of this in a game, hehe :)