Many of them are, yes. And so are many atheists. And the purveyor or purveyors of a blog I recently saw with a post with the title quoted in this post's title -- dumb as posts, so to speak. Another title on their blog is We'll Pay $200 To Charity For Every Muslim Who Can Prove He's Peaceful. You don't need to be Ludwig Wittgenstein to perceive that they're neither especially charitable, nor able to see a peaceful Muslim standing right in front of them.
There's no shortage of stupidity anyplace I've seen. "Well, Steve," you may ask, "have you ever seen Princeton's Institute for Advanced Studies?!"
And as a matter of fact I have not. But I have spent some time in some other world-class smartypants institutions, so there.
You may press on and say, "Well riddle me this, Smartypants -- do you think maybe it's kinda stupid of you to spend so much time online with so many stupid believers and stupid atheists who are constantly seeking each other out for the sole purpose of calling each other stupid? Huh?!"
... Maybe. Yeah, now that you mention it, maybe it is.