Why does most of society (at least the english speaking society) think that hitler was the epitome of evil?

My answer would be his persona, he was a very affluent speaker and was very smart at using propaganda. Nazis pioneered the usage of video propaganda. He was in the public's eye, thus the world's eye. Also you have to remember that history is written by the victor, so history from the allies perspective is of a man who nearly conquered all of Europe, and tried to conquer the rest of the world. Thus he has been demonized (not that he needed help on that front). However, I would like to say that the main reason he is regarded as the epitome of evil is because he had so many people slaughtered and his actions led to the deaths of so many more.