Why? This is 1942 and if anyone said "Now that's just not cricket!" then this person and their family would probably be dragged off to 'have a chat' with the Gestapo. They might even come out of it alive. This
is Nazi Germany after all, totalitarian state and all that goes with it and a LOT more. So if Hitler goes and finally says in clear language "We are going to exterminate and eradicate the jews, not from our sphere of influence, but from our very planet! Germany will not cease until ALL traces of the Jew have been expunged from the Earth!"
Because lets be honest, he and his cronies had been pretty much saying the same damn thing from the pulpit, just in political language (see 'final solution' which was basically 'kill them all' but said in a political way).
There will be LOTS of Sieg heils and salutes and in the West there would people saying that he was crazy or something, but thats about it. If you spoke out against this then you'd be LUCKY to be shot if the Gestapo and Friends wanted you dead. After all, that's far too quick for people like that.