Why can't death-row victims be "HUMANELY" culled for cannibalistic purposes?

well i was just pondering, since its highly prejudiced to think its ok to eat anything other than your own kind. I do think cannibalists have a valid point when it comes to suffice their taste, and whats unethical about humanly culling death-row sentensees to be packaged and sold as human meat in specialty meat boutiques which already sell frog, dog, French and German horses, Australian gator , crocs and kangaroos. I don't see the harm innit...