4. He's Too Often Used To Give Other Characters Story Arcs
There's a term in professional wrestling for people who routinely lose matches to help other wrestlers look better and get them over with the fans. They call these guys "jobbers." They rarely get the glory. They just do the job and move on. In episodic television, Daryl is the ultimate jobber. Not only does he always play second fiddle to Rick, but with the exception of his relationship with his brother (and one specific, soul-baring episode with Beth), Daryl has always been used to stoke the fires of other character's development. He single-handedly turned Carol into a recurring character. He somehow managed the impossible feat of making both Beth and Merle tolerable at different points in the series. This may not seem like much of a critique, since someone like that is an asset purely from a writer's standpoint, but it's frustrating to see it happen repeatedly because it almost always takes the focus away from his own emotional arc. To be fair, the writers finally started cracking away at the layers of mystery at the end of Season 5, but now it's time for a character to be of service to Daryl's needs.