It may not be a misconception if I simply disagree with the point you make. My point is simply that: If faith in a god requires belief without tangible evidence, then belief in no-god also requires the same faith. An atheist has to state that they KNOW with certitude there is no god, and they make that statement without any tangible proof. A believer makes the same statement but only in favor of a deity, and still without tangible evidence. Atheists fall into the same problems that believers do when it comes to proving a something that can only be accepted. At some point a believer or an atheist decides that they will believe as they do. That is an act of faith. Bill Maher's analogy is not a good one because it is using something that can be observed, which faith in a deity or no-deity does not include by the nature of the object we are discussing. Toothfairy is a known social construct, Cthulhu comes from literature and flying spaghetti monster is satire, so these are not helpful to your point, IMHO.
This does not apply to agnostics who say they are not sure one way or the other. I have no skin in this game btw, I am neither a believer, agnostic nor atheist. So think how that is possible!