Is it? Unrelated to that, I stumbled upon "ProAction Cafe Singapore- thinking collaboratively", which described an event whereat, among other questions, this one was discussed: "Are atheists basically religious at heart?" I can't speak for others --- actually, I don't know for a fact if I know any other atheists --- but I think if one were to seriously describe oneself as an atheist, it's probably not out of a flippant attitude to religion or religiosity, and hopefully out of a genuine consideration of ideas about religion and faith.
The second time I happened to mention being atheist was last night, at Zouk waiting for John Digiweed to show up. You could say that a dance club with pounding music too loud for you to talk is an odd place to have a conversation about religion --- or you could say that given the moments of communion one might find through that music, with it, that it's perfectly apropos.