Because I've encountered plenty of different atheists both online and IRL, and we've had a fair amount in common - similar view on politics, science, philosophy, etc.
Oh, and can I get a link to that? It sounds really cool. Unless you mean arbital, which I already saw.
My point is that I've met plenty of people, period, who I've had a fair amount in common with. Rarely are the religious people fundamentalists, but one of those friendships was founded on religious debate. I dislike echo chambers most of the time, and some of the atheists I know are kinda dicks about it. Which I don't really put up with because being condescending to someone about their beliefs is a shitty thing to do. Besides which, there's a lot of different possible philosophies within atheism, just like there's about a thousand or so different sects of Christianity. Some people are nihilist, some existentialist. Some are still spiritual, others very materialistic. Nature of good and what we should strive for to be good is a big one there, too. That's the type of thing you build a community around. Around the belief in debate and contesting ideas, and trying to find truth, or about doing good things. Not about 'we
don't believe there's a god! Take
that!'.
That was what I was getting at. Also, I believe DwArfY1 was saying that you are mistaken as to it being part of a broader pattern.
But yes, I meant arbital. Took me forever to find/remember the name of it.