They can, after all atheism is a belief just like any religion out there. You think of agnosticism - which imho is a much more reasonable stance at all
I am not so sure about your definition of atheism vs. agnosticism.
http://atheism.about.com/od/aboutagnosticism/a/atheism.htm
"Once it is understood that
atheism is merely the absence of belief in any gods, it becomes evident that agnosticism is not, as many assume, a third way between atheism and theism. Thus, it is clear that agnosticism is compatible with both theism and atheism. A person can believe in a god (theism) without claiming to know for sure if that god exists; the result is agnostic theism. On the other hand, a person can disbelieve in gods (atheism) without claiming to know for sure that no gods can or do exist; the result is agnostic atheism. An agnostic atheist wont claim to know for sure that nothing warranting the label god exists or that such cannot exist, but they also dont actively believe that such an entity does indeed exist."
In other words, A means without and gnosis means knowledge. Hence, agnostic: without knowledge, but specifically without knowledge of gods.
Therefore, an agnostic is not simply someone who suspends judgment on an issue, but rather one who suspends judgment because he feels that the subject is unknowable and therefore no judgment can be made.
An atheist on the other hand states that he/she simply doesn't believe in gods, but that doesn't mean he/she is not open to the possibility that they may exist.
Gordon Stein wrote in his essay The Meaning of Atheism and Agnosticism:
http://atheism.about.com/od/aboutagnosticism/a/what.htm