One of my main areas of research is the Jesus myth theory. I have done a lot of work in refuting it but the question remains: Why has theory returned? Komoszewski, Sawyer and Wallace suggest some reasons in their fantastic book Reinventing Jesus.
“How could the idea that there is nothing unique in Christianity gain a footing today? A combination of factors contributed to this resurgence. The postmodern interest in spirituality, coupled with its increasing lack of historical grounding, has been the main ingedient. But the icing on the cake is ready access to unfiltered information via the Internet and the influential power of this medium. The result is junk food for the mind—a pseudointellectual meal that is easy to swallow as it is devoid of substance.”