This article is worth noting simply for this statement "...nonbelief is not just an argument but a cause, like environmentalism or muscular dystrophy." There's two reasons for this. The first is that atheism or humanism as they have called it have moved from carrying the idea of atheism as a private matter into a public arena. In an era of Twitter/Facebook where we are encouraged to post our innermost thoughts and many do, it is the logical conclusion that what an individual thinks/believes about the world can be converted into a cause and shared with other people. The second is that causes are currently sexy, arguements are not. You can market a cause, create t-shirts for it and make it cupcakes. A cause has an arguement for a particular view of the world at its core and giving an arguement a cause allows that arguement to move from a disparate, extremely peripheral idea that, in terms of atheism, has seemed to linger at the edges of Western culture, to, by the vehicle of its now hip cause, to gather force and move from a extreme peripheral element closer to a core element of Western culture. Causes currently seem to be 'the thing' and if the people in the cause that you are attracted to are of a similar mind and friendly it substitutes nicely for religion/church.