Whether this area was in fact unusually hospitable to revivalism and social reform movements is now considered to be open to question, but this is beside the point. It was Cross’s methodology and the contours of his argument that struck his readers as innovative and worthy of imitation.
This region's receptivity to revivalism and social reform movements is now in doubt, but that's not the crucial point. What Cross's readers found remarkable was his approach and the framework of his argument, which they regarded as trailblazing and worthy of replication.