You don't see a difference in authoritarianism of British "banning the public wishing of mass death" and Nazi "requiring the public wishing of mass death? "
The equivalancy drawn in the joke is part of what makes it funny.
He's probably a German.
Is it funny? I'm a Brit and I don't really get it. Maybe because my ancestors were German jewish and had to get the hell out. WW2 wasn't really about being envious of the Germans.