The other side of the argument is that Hitler cannot be ignored and written out of history. History is what it is and ignoring the truth of history does not change that history. My personal view is that the evil that Hitler perpetrated against the Jews and against Europe in a more general sense must never be glorified but equally it must never be forgotten. Hitler was just a man and we must never forget the evil that ordinary men (and women) can do.
The waxwork was hardly a glorification of the man. It depicts him as defeated and sullen.
However, this was obviously not enough to appease some. A man ran into the exhibit and ripped Hitler's head off earlier today. I would reckon there might be plenty of people who wished someone had been successful in ripping the man's head off way back in the 1930's.