Carl Sagan knew that he never quite made it as a physicist, but he really believed in experimental science, and accepted a role at Cornell as a populariser to nonscientists. That mindset allowed him to create a TV "cosmos" that was exciting to scientists and nonscientists alike without being close minded. Carried that thinking and commitment all the way to "Contact."
Dawkins was always in it for the money, and neither Richard nor Neil stayed alive and viable as scientists--or, really, seemed to care . . .
I'm not even convinced they are true "disbelievers."