They in some cases add or extend flashbacks to build up some stuff. whether it be a character's overall personality or an extended explanation of something that happened (ex. the explanation of the Izanami and Izanagi).
And yes, many of the studio members (not Pierrot as a whole) are Hinata fans, I thought this ending theme made it perfectly clear (listen at your own risk) :|
Though I myself tend to side with the anime, and this is coming from someone interested in writing. Yes, some stuff may be questionable, but at the end of the day, the good outweighs the peculiar.