My cousin posed the title question to me the other day, after observing the behavior of a friend. He's agnostic, educated, works a job in business and is, like me, a foodie. She described how dogmatic he is about the uses and presentations of food. How he tries to "convert" people to his gastronomic choices and spread the gospel of his culinary experiences. How, when in his presence, she sometimes felt she got insight into the experiences of those who complain of the overbearing approach of some Christians. If you put his behavior into the context of the concept of non-theistic belief, it very much mirrors devout followers of any religion.
My first exposure to the concept came on the back of rapper KRS-One's "I Got Next" album. It included a brief introduction to the Temple of Hip Hop. If you read up on it, you'll see that it's not actually presented as a religion in the traditional sense...I believe the effort of the organization is one toward awareness and understanding of an often misunderstood form of music...but...it, like many things, could satisfy the needs of a person who is inherently religious, or who wants to be a religious leader.
I do believe though, that religion has a purpose, and feeds a need that we as humans, at some level, all carry within ourselves. As Christians, I believe it gives us context for many spiritual concepts and a framework for the practical application of many forms of discipleship.