Why do so many Americans judge Muslims based only on the actions of the 9/11 hijackers?

Hitler was not a Christian at all, just because people do things in the name of a religion or a God does not mean they are true followers of that God. A lot of bad things have been done int he name of God whether it be the Christian God or Allah or Shiva or any other god. I have never judged Muslims or any other religion and I know a lot of Americans who have no ill will towards Muslims. Ignorance and the need to blame is why some Americans blame all Muslims for the actions of a few. And racism is not specific to the white man regardless of what some ignorant people think. And has nothing to do with stupidity it is ignorance. I know that you are not judging all Americans from what I read, but some of the people answering calling the white man stupid and Americans stupid are just ignorant. Anyone who judges another will be judged more harshly then those that follow the full word.