Human-hide wallets and canibalized embryos

Was it a good idea for Nazis to try to make wallets and lamp shades out of the skin of killed prisoners? Ok, so killing people because of their ethnic background is against some people's ideas of traditional morality, but if they are going to die anyway, why should the bodies go to waste?

How about concentration-camp slavery? Sure, slavery is against some people's personal moral values, but if the prisoners are going to die anyway, why shouldn't society benefit by working them to death? At least some good would come out of a bad situation that way.

(Sorry, but these gruesome analogies do have a purpose).