Ironically, what the Nazis did in the extermination camps was mass executions, i.e. the very thing anon finds wasteful.

The Extermination Camps only served the purpose so exterminate people(couldn’t have guessed). After 1942 however, Concentration Camps were used to produce stuff and to lend the prisoners to other businesses. Before 1942 Concentration camps were exactly what Anon described. Treat your prisoners poorly, so they die.