There are a lot of smart Christians. Someone like Ken Jennings is probably smarter than any of the individual atheists you mentioned and that guy’s a Mormon; who is more mocked among believers in God than the Mormons? The reality that there are many intelligent Christians is lost on a lot of the people who rail against how stupid religious people are all the time. It definitely says a lot about someone’s own intellectual shortcomings if they think of people with supernatural or faith-based beliefs as categorically stupid.
It’s a far more interesting exercise for an atheist who considers themself smart to ponder why someone like Ken Jennings could have such vastly different world views than they do, because you cannot in good faith dismiss it with “he’s stupid.” Then you realize the same goes for any person of faith.