You know it is possible to be an idiot and still know lots of things. Plus, like Katie's just said, idiots aren't bad at all, I know lots of them and some are thoroughly entertaining people. Sure you can't talk to certain people about stuff they don't/don't want to understand, but that doesn't stop them being fun to be around.
Also, why bother classifying millions of clearly very different people into one very derogatory stereotype. It's just lazy.