An interesting article on this topic:
In brief, witchcraft is an ideal avenue for the postmodern view of life. The modern view understood life and religion through scientism. Due to its focus on the methods of natural science, scientism rejected organized religion and the existence of anything supernatural. The ideal faith of the modern view was atheism. The postmodern mind, however, both recognizes that science does not have all the answers and is skeptical of organized religion. For example, many postmodern thinkers claim to be “spiritual, but not religious.” The combined emphasis on personal subjectivity and skepticism toward organized religion is the fertile ground in which witchcraft has grown.