I have to admit, I've never really understood this line of thinking. Theists started using the term first to describe nonbelievers, eventually the label was adopted as a response. I agree in a sense it doesn't provide much useful information. It tells you nothing of my personal beliefs, my politics, and very little of my personal philosophy of life. However in a country like the US, at least the part I'm in, not believing is a big thing. It's a distinction that can have a major effect in your life. From social and business isolation, to loss of access to parts of society, to being part of a subgroup readily mocked by parts of our supposedly representative government. Having a joint label that will help identify other people of similar mindset, or tribe, is a good thing.