Cannibalism: Why is it such a big deal?

Why is cannibalism such a taboo in civilized society?

A coworker of mine just made a very interesting point. He said that the only animal he would possibly feel justified in killing for food is a person. That makes sense to me. I mean, what animal is more likely to have done something to deserve it?

Deer, cows, sheep, pigs, these animals have done nothing wrong. They are innocent, and we slaughter them daily to fill our fat selfish bellies.

And why is it such a taboo to eat people anyway? I'm sure the thigh or ass of most any person could be prepared in such a way as to be every bit as tasty as any Filet Mignon you've ever had.

All those people on death row across the country? Kill them and feed 'em to the prisoners! It would save us tax money! People who steal? Cut off an arm and sautee it up for the dining pleasure of the wronged party. And how about all those old people who are just going to die anyway and fill up some cemetary? That's just so wasteful, not to mention environmentally questionable. Let's eat 'em!