Jack Carlson writes about atheism's big fail. I think he's mistaken on two counts. First I think there is an atheist community. More importantly, I don't see any particular reason why there should be an atheist community, or why any specific level of participation — including none at all — should be viewed as a failure.
There are two levels of atheism: people who do not believe in any god(s), and people who self-identify as atheists. I've observed that many people who do not have any belief in god(s) in any meaningful sense do not or actively refuse to self-identify as atheists.
Carlson is correct: "Other than that one specific philosophical opinion, atheists do not necessarily share any other conclusion, interest or attitude." Communities do indeed form around shared interests. Since atheists do not have any shared interests, it's natural that there would not be an atheist community per se. It's not, as Carlson suggests, a "failure of marketing". There's no actual shared interest to market.
What we do see is a lot of different communities — political, philosophical, scientific, recreational, professional, etc. — forming that include or are dominated by atheists.
There are a lot of atheists I have absolutely no interest in being in any type of meaningful community with: Libertarians, Randians, Republicans, new-age crystal woo-woo. There are other communities — e.g. skeptical anti-woo investigators, advocates of evolutionary science, pro-secularist political activists — who, while I admire their activities, do not engage in activities I have any particular interest in.
I resent being called a "failure" and chided because I don't drop my particular interests and take up some manufactured superficiality necessary to be in an "atheist" community, a group of people 90% of whom I simply do not share any meaningful interest. Quite the contrary: I'm proud to be a member of a number of different communities as an outspoken and unapologetic atheist.