re: Daryl Dixon

All zombie shows/movies jump the shark as soon as other humans become the main, central threat rather than the zombies. Once the zombies have been sidelined to a supporting role, an occasional threat, a convenient plot device, then it stops really being a zombie show.

Of course, that almost always happens, because of the zombie allegory tropes of "other bad," etc.

Season 1 of the Walking Dead was so amazing because it maintained the zombie threat as so real and so central for so long. As the zombies became more mundane and moved into the background over the ensuing seasons, the show had to rely more and more on tricks and gimmicks to keep the audience interested. Negan breathed a little life into the series because he was such a great bad guy and gave the show another interesting main threat.