Muslims - please explain this?

Why is it, that when I refer to Christianity, or Judaism, or Hinduism, or Buddhism, as silly superstitious primitive nonsense, then I'm told that I am an atheist, and that I will suffer eternal torment (or whatever). But when I say the same thing about islam, then I am told all this, AND I am told that I am a racist? Why do you think everyone who does not like your religion is a racist?