Because to be honest, as much as I love to look at wolves, lions, tigers, bear cubs, and the like (cows, horses, ect) I kinda sorta prefer my own race over them. If I had the choice to save a mortally wounded dog and a mortally wounded human, I'd choose the human. You know why? Because we are above the animals.
From a Christian pov, we were put above the animals and charged to take care of them. God never said that we couldn't eat them and that killing them for food and fur was a sin. No, you know why? Because animals are just that, animals. They have no concept of right and wrong. Does that mean we should be cruel to them? No, it just means that we are above them not the other way around.
Evolutionwise, well, seeing as how we are higher on the evolutionary scale then, let's say, a sheep, I think the answer is a given. Food chain wise, we're the smarter because that's how we evolved (apparently).
I have no problem with people who wish to eat only vegetation for the rest of their lives. Some people do it because they genuinely hate the taste of meat. If you do it because you like animals so much that you don't want to eat them, that's fine, just remember that the rest of us think they taste good and look cute. And also, keep in mind that animals cannot compare to a human so don't treat them like they are. Instead, treat them how you would treat a living thing because they are living things. And that also means, giving them a quick easy death before you skin them and take the meat off their bones to give you strong muscles, better stamina, more protein then beans could ever give you, and heal your crohn's disease (if you have crohn's it is best to not go vegetarian unless meat screws up your stomach).
*takes deep breath*
I believe that I have made my point.