The man wrote some of the best Superman stories of the post-COIE Superman and was keen on re-introducing pre-COIE and Donner film elements into his stories, which was a great formula in my book. Plus, we all saw how badly JMS sunk the franchise once he took over. Had DC given Johns, and possibly Grant Morrison better control over the character before the reboot, it probably would have been in much better shape.
EDIT: Can a moderator remove that extra "have" in the title? Thanks!