The Reich’s brainwashing of racial purity was so successful many didn’t question it. If you wanted a job or a promotion you “did your duty” even if that meant mass murder. However, this is not an excuse, in war time perception of “right” and “wrong” get muddied, but that usually occurs on an individual scale, not when it comes to the assist and/or participating in genocide or a bastardized form of euthanasia (killing your own soldiers who were left mentally or physically injured in battle).