Since "string theory" at this time is simply a mathematical language that enables us to discuss the interactions of the fundamental forces in the Universe, I'm not quite sure what their point is concerning it.
It's pretty obvious to me that it has a parallel/cognate language used in the Judeo-Christian tradition to discuss God, and that's pretty doggone profound. Consequently, it would seem to me that it would be much more likely for the anti-religion crowd to be against "string theory" than the religious minded.