Board Thread:Dark Souls/@comment-63.153.23.3-20130729052232/@comment-18016240-20131012001822

It probably has to do with the Crystal and Dark Sorceries, unless you're referring to the fluff/lore, which has to do with how sorcery comes from the dragons instead of the gods like miracles. (pyromancy has the same problem, but the pyromancers have more or less worked around it by staying in the Great Swamp for the most part.