Why do many English think that believing in Creation is stupid?

I would surmise that it is based on the fact that Creationism is taught as truth rather than religious belief in some schools in North America. It has nothing to do with Catholicism or Creationism per se. I know that is why *I* think Creationism is stupid - not because I'm looking down on anyone's religious beliefs, but because I find it fundamentally irresponsible and downright stupid to teach it as truth in schools.