More accurately, I think, agnostic atheists don't rule out the possibility of god/s existing; they simply don't find the arguments convincing. Certainly I've never come across one that wasn't superficially compelling at first blush, but which on deeper reflection was just smoke and mirrors.
At the age of five, Skagra decided emphatically that God did not exist. This revelation tends to make most people in the universe who have it react in one of two ways - with relief or with despair. Only Skagra responded to it by thinking, 'Wait a second. That means there's a situation vacant.'
