David Plotz startled journalism yesterday with the announcement that he was leaving his job as editor of Slate for the neighboring position of editor at large of Slate. He assured his cohort in a blast e-mail that there’s “no secret reason” for his departure after six years as editor and 18 years in various positions at the online magazine. His deputy, Julia Turner, is taking over the enterprise.

In an interview today with the Erik Wemple Blog, Plotz revealed that he has some things to say about the vitality of organizations. Let him riff: “I’m not learning from the job the way I learned from the job four years ago or two years ago. … I think Julia will bring a new perspective and energy and wisdom — the people she’ll elevate are incredibly talented, so I think Slate’s going to be better. All those people, having them tackling some new thing, it’s gonna be great for them. … I do think that leadership should churn, it should churn because you get into habits and you don’t pay as much attention. … Things critically important to the institution become less critically important to the leader,” says Plotz, who talks of the need for leadership to “gnaw” into the challenges that pop up in this industry. “I could gnaw, and I would gnaw with my back molars. You need someone gnaw with their incisors.” He pointed to a critical managerial “trade-off”: “What happened with me is I reached the point where the accumulated wisdom that I have is not worth the diminished passion,” notes Plotz, who oversaw a staff of about 50 editorial employees.

With that flourish, Plotz furnished some convincing evidence that there really, really is no secret reason behind his departure from a thriving Web property. Should any such reason present itself, says Plotz, “I will be shocked or surprised, since I was the one who instigated the entire thing.” About six weeks ago, he says, he approached Jacob Weisberg, chairman of The Slate Group, with the news that he was out of there. Weisberg responded by asking if more money would keep him on board. “It was a non-starter,” says Plotz. Weisberg confirms this version of events: “It was totally his call,” he says. Perhaps further evidence that Plotz wasn’t chained to his Slate position: He applied for the spot of New America Foundation president, a position that went to Anne-Marie Slaughter.

Slate, a property of Graham Holdings Company and, before that, the Washington Post Co., was profitable last year, say Plotz and Weisberg, and has done well over the first half of this year. So Plotz didn’t bolt to avoid some miserable downsizing project, though he acknowledges that the business environment for a digital magazine is perpetual storm: “It wouldn’t at all surprise me if Slate has a bad year or blowout year, the best ever,” he says. After Slate’s separation from the Washington Post Co., the magazine beefed up to add certain functions — like accounting and ad operations — that its former parent company provided.

Asked to name his Top-Five-Best decisions of his tenure, Plotz cited:

• Launching the “Fresca” program, in which reporters escape from the rigors of daily posting and go long on a project.

• Expanding Slate podcasts. For anyone who would dispute Plotz on this matter, he has a name for you: Stephen Colbert, “a megafan of Slate podcasts,” says Plotz, who insists that Colbert commands the “smartest and best audience in the world. … If there’s one person you want listening, it is Stephen Colbert.” As Slate noted, Colbert once said, “Everybody Should Listen to the Slate Political Gabfest.” He also said, “It just puts me right to sleep at night.”

• Appointing Turner as deputy editor.

• Hiring Dave Weigel, the roving political and media commentator. Not only does Weigel write great stuff, says Plotz, but also he helped open Slate up to other Web talents.

Asked to identify his five worst decisions, Plotz didn’t itemize: “I’m sure there are tons of them,” he says.

For some time now, there’s been something of a disconnect at Slate: It has done deep coverage of women’s issues under the XX section, yet it has a history of being run by men — first by Michael Kinsley, then by Weisberg, then Plotz. The guys’ run at the top has now ended. “I am thrilled that Slate’s new editor is a woman,” says Plotz, noting that Turner is “tremendous” on the merits. “I do think it sends a signal. Opinion, thinky magazines have tended to be run by guys,” he says.