There is a clear reason - to make them uncomfortable. Nobody forced them to work there, and it is obvious to everyone what kind of future they are building ther

There is a clear reason - to make them uncomfortable. Nobody forced them to work there, and it is obvious to everyone what kind of future they are building there. If you exchange your soul for a good paycheck, this is just what you get. The alternative is "Oh, you work at Schutzstaffel? That's cool!". That he has done is morally correct.