A valid point, until you realize that prior to 1937, not very many people were aware what was really happening, and those who did know were treated as though they were crazy. The propaganda machine he had was one of the best of its time.

And in the US, people tended to cover their ears and yell "LALALALALALA" at the mere mention of Hitler's name. In 1940, Charlie Chaplin produced The Great Dictator, one of the greatest political satires ever made. But Chaplin himself is on record as saying that he would not have made that movie if he was aware of the extent of the Nazis' atrocities.