Many notable atheists believe in some powerfully stupid stuff, thereby eroding the credibility of all atheists.
To be fair, maybe an editor inserted that line. Okay, now that I've been fair; regardless of who wrote it, what kind of a twit starts off an article bemoaning faulty thinking with such a logical howler? Vanquishing a tribal desert god doesn't entail inheriting that fabled omniscience.
The only thing that reasonably follows from a profession of atheism is the assumption that here, we have a person who either successfully coped with the loss of a psychological center of gravity that often accompanies breaking the emotional and cultural bonds of faith, or one who was never raised to consider religious belief an essential piece of personal identity to begin with. Atheism doesn't actually require Herculean feats of logic, and as such, says nothing meaningful about one's imperviousness to "lesser" irrationalities like pride, fear, anger, or groupthink.