According to Deadline.com, sources say that Darabont, a feature film helmer and multi-Oscar nominee before moving to the small screen, was unaccustomed to the fast pace of TV production, and "never quite adjusted to the daily grind of producing a TV series."
Production recently got underway for Season 2, which is due to premiere on AMC in October. There's been no word yet on whether Darabont, who is also an exec producer on 'The Walking Dead,' will remain on the series in some capacity.
So, why has Darabont quit? Was it because he couldn't take the pace? Or was it because of rumored budget cuts?
Darabont's abrupt exit has caught observers off-guard. He seemed as passionate as ever about the series at Comic-Con last week and, after all, 'The Walking Dead' is his baby -- he spent almost five years shopping it around as a TV series before finding a home for it on AMC.
Although it's based on Robert Kirkman and Tony Moore's comic books, Darabont has received the lion's share of the credit for adapting 'The Walking Dead' into one of the most successful shows on cable.
Back in December Kirkman said that the original plan for the series had been that Darabont would be showrunner for Season 1 and then move on, leaving room for Darabont's "go-to guy," executive producer and writer Charles "Chic" Eglee ('Dexter,' 'Dark Angel') to take over in Season 2.
But then Darabont changed his mind and decided to stay put, so Eglee quit. "Chic Eglee is a high-level television writer. He was brought onto 'The Walking Dead' with the idea that Frank was going to work on the first season and then go off and do movies," Kirkman said. "Chic didn't want to be second-in-command on a show when he's used to being a top dog, and so he decided to go off and do something else, which is something that happens and is not a big deal."
Of the total six episodes in Season 1, Darabont wrote two -- the pilot and follow-up -- and either co-wrote or re-wrote the other four. And of those four, one was written by Kirkman and the other by 'HawthoRNe' alum, writer/producer Glen Mazzara.
Darabont toyed with the idea of using only freelance TV scriptwriters for Season 2, but in the end he stayed with the traditional writing staff model recommended by AMC and tapped Mazzara as an executive producer and his number two. Mazzara has showrunning experience, so he could be a possible replacement at the helm.
Publicly, Darabont has had almost unanimously positive things to say about his TV venture, but in a May roundtable with 'The Hollywood Reporter'he hinted at trouble behing the scenes.
Addressing reports that AMC wanted to slash the budget for Season 2 of 'The Walking Dead,' Darabont said that "Creatively I have no complaints thus far ... But I believe if they do move ahead with [the budget] they're talking about, it will affect the show creatively ... in a negative way. Which just strikes me as odd. If you have an asset, why would you punish it?"
He added, "They count on your loyalty to your crew and to your cast as leverage against you."
'The Walking Dead' Season 2 premieres Sunday Oct. 16, 9PM ET on AMC.