Okay, here are my thoughts:
As much as 4A screams the jumping the shark moment, I honestly think it happened before.
In my opinion the moment was Neal’s death. It is not necessarily the death itself, but how it happened and what followed. The fact that they forgot about him 2 episodes later didn’t help, the fact that Zelena, knowing what Neal means to Emma, think that she would kiss Hook like few days after Neal died, this is not Zelena, this is the manipulative writing, which killed Neal for Emma and Hook to work. The way they wrote Emma and Neal didn’t allow for Emma and Hook to happen. Season 3B already had the rushed pairing of Robin and Regina, and now we get Hook and Emma. Neal’s death symbolizes the end of the show as being a show about family and hope, which was the main narrative for season 1-3A, since Neal had a lot of familial connection to the main characters. The show since then became about ships and this has become the thing that drives the show, not to mention that since then the writers has cared about the eyes more than the actual story they try to tell.
"All your questions are pointless"