A Quokka Dreeds its Weird

I can't say anything for sure, but the writing environment of the Heian court strikes me as something more like fandom than formal publishing. You wrote for a small circle of friends, in women's language (low status, but relatively free from male censorship), published chapter by chapter and got feedback immediately, and (in my view) pushed fantasy elements to extremes. In this case, I'd say that the beauty of female vulnerability is being pushed to the edge of the id vortex, both in the context of females unable to resist Genji's advances and in Murasaki's helpless innocence in the face of Genji's mad desires. A second line might be to emphasize the depth of feeling by adding elements not acceptable in that culture, the similar to the way slash writers often have their characters face and overcome homosexuality taboos. I don't take the Tale as either a historical document or moral guide, and I really doubt that the author meant me to.