The very idea of uniting atheists is "out there." They are not all subscribers to the big bang, the primordial soup waiting for a spark, survival of the fittest in some Darwinian evolution. The only prerequisite for a person claiming he's an atheist is the ability to claim it. Legitimizing that claim means not believing in a monotheistic god. It says nothing of what they do believe in. So I say "Good Luck" to anyone trying to herd those cats.
Most atheists can change their view in light of new evidence, but I think it's important to atheism for them to continue to feel free to argue and form differing opinions about what the evidence suggests.
Having been fooled into being a JW could have made me a scoffer at others' religious beliefs. But having freed myself down my own spiritual (meaning 'not materialistic') path, I fully understand that people hold beliefs or develop beliefs that give them a sense of purpose or enlightenment or belonging. There is more to our lives than just cold facts and the search for them. We do need to appreciate the reasons why people are religious and different.
I used to love Greek and Roman Mythology when I was young. But I heard a quote from some native American that calling some culture's stories myths was a way of dismissing them. They are legends. Legends may not have a 100% factual quality, but they developed for some reason. They hold value of some sort. The Bible, especially the OT, is such a group of legends. There are valid reasons why they developed in such a way. I scoff at the Flood legend with the best of them, but deep down, I know there are lessons in there. They just don't involve an actual sky daddy.