Sam Harris can't persuade the Taliban that women are worth caring about. All he can do is to persuade the rest of us not to tolerate the Taliban.

I dunno, if the Taliban magically became convinced of the "objective fact" that their god didn't exist, I suspect that they'd be more willing to listen to arguments about the value of girls' schools and such. If there really were an evil bastard deity out there sending people to hell for not following the rules that the Taliban imposes, then, well, it would be better to force women to wear burqas and keep them out of school than let them end up as yet another victim of said evil deity.