Sure, theists show up here that we would be better off without, but that is not because they are theists. It is because they are douchebags, and we get plenty of the atheistic variety, too.
Even if the open windows of science at first make us shiver after the cozy indoor warmth of traditional humanizing myths, in the end the fresh air brings vigor, and the great spaces have a splendor of their own - Bertrand Russell