I have to agree with the position taken, as well as with the other atheist/agnostic poll, that it's not a question that can be answered in either/or terms.
People believe or disbelieve things for different reasons. One person may be atheist because they see no evidence to support that there is a god. Another may be because they feel that there is a logical reason why there can be no god or that contradictions in believers lead them to believe there probably is no god and their emotions push them the rest of the way. Someone could be raised atheist and taught "reasons" why there is no god and simply follow what their taught, they may question it and find what they believe is evidence that there IS a god and become a theist. They may be raised a theist and question it and find evidence that contradicts the reasons they were given for believing and conclude there is no god. They may simply be taught and never question it, or question it and find evidence in their own mind to justify it.
Emotions, thoughts and perceptions play a HUGE role in how someone will process "evidence", including how it's presented to them. They may be shown a train of thought that "logically" concludes one thing or another by someone who believes that thing and thought up the "logic" to support it...there may be contradictions that someone who doesn't believe can easily point out...but they're not going to be presented by the person trying to prove their point.
Seperating emotions and desires from evidence and observations is difficult, and some people chose to ignore evidence or emotions in favor of one thing or another, to maintain the desired feeling. If they took the time to evaluate that evidence, they may determine it disproves their belief (in their own mind) or they mind find it disaudes them from it. Most people chose to stick to the feeling they've found comfortable in favor of challenging their beliefs.
Personally, I'm an atheist. I used to believe in god, but I never REALLY believed. I was told there was a god, I had lots of reasons given to me as to why there MUST be a god but in the end after all my soul searching and attempts to connect to that god, whatever it was...I felt that everything I had experienced lead me to believe there was none. That most of the things I felt as "god" were myself, my own emotions, trying to fufill an expectation or desire that I had and I saw the same thing in others. In myself and others of similar belief I saw a desire for a feeling of purpose and acceptance, love, validation. Often a desire for a divine intervention or explanation for tragedy or loss. What started to turn me away from these explanations was the realization that most of them revolved around avoiding the emotion or the acceptance of situations and simply saying "it's god's will" or "well, he works in myseterious ways" or, what made me actually angry at times "maybe it wouldn't have happened if I just loved god more".
Maybe I'm getting too in depth for this subject...but my point is that you have to take into account that you're not dealing with abstract concepts alone, you're dealing with people and people's perceptions and reactions are affected by a multitude of things. Logic is a hard thing to isolate, so while some of us may feel we are atheists because we've taken the time to seperate what we feel is reality from what our emotions and desires for comfort and escape are...there may be others who are in the same place for different reasons that are as flawed as those who take the opposite view.