The complete separation between Dixing and Haixing disappointed me too. If I was going to have a different ending to the drama, this sort of scenario is what I would want. I also felt, though, that with almost every "villain" story, the show emphasized the idea of making bad decisions with bad consequences based on incomplete information. Ye Zun's backstory fit perfectly within this narrative. So in that way, I thought that it complemented the narrative moods and goals of the show.