Sad isn't it. Using that logic, we might as well write off German innovation in the sciences and arts because of the Nazis, Chinese inventions and culture because of Mao or even American culture and ingenuity because of Adam Sandler.
Hitler and Mao were in power for a very short time - whereas mohammad, to muslims, rules from the 7th century until forever. The koran and hadith have ruled every thought and action of muslims for 1400 years. Germany and China regressed under Hitler and Mao, but it was a temporary regression. Islam is permanently regressive. btw, I'm an aussie, I have no idea who Adam Sandler is.