In our modern society, we are very far removed from the food we eat. How often do we eat a steak at a restaurant and think about the actual cow that it came from? I'd argue that for the vast majority of us, the thought of the animal never crosses our mind.
Some people cringe at the thought of seeing an animal being killed but will eat a cheeseburger. To me, that doesn't make sense. Ordering that cheeseburger is ordering an animal to be killed.
"But the animal was already dead." Sure, but now the restaurant will order one more burger next time to meet their inventory needs. (this example works for leather and fur, too)
We should at least be willing to recognize the sacrifice of the once-living being.
Vegetarian? Plants are being killed for you to eat, too. We can't escape death. It's a part of life, as they say.