Why are there more atheists here than those who believe in a God?

I mean, this is the Religion and Spirituality section. I guess one would expect more people who has a belief in a God than those who don't. Why is that? Is it proof of just how much these people want to welcome a certain belief in their life? Or are they simply lurking around here and voicing out what little opinions they hold in the world for they comprise only 2.5% of the world's total population?