Several people, including Clark Lindsey and Keith Cowing, have linked to this Onion article:

“It’s always ‘Are the solid rocket boosters functioning at full capacity?’ and ‘Do the liquid oxygen prevalves operate as required?’ with John,” Discovery commander James Reid said. “If it weren’t for that guy, we’d already be in space by now.”

In addition to his insistence on mission coordinates being 100 percent accurate, Wilkins reportedly spends all his time obsessing about Discovery’s general purpose computers, which ignite the main engines and ensure that the craft can safely reach the speed of 18,000 mph.

“Is there anything John doesn’t worry about?” said Michael Dennigan, the shuttle crew’s second-in-command. “This isn’t rocket science—you’d think he’d try to relax a bit.”

Since he was assigned to it last year, Wilkins has aborted the NASA mission for a wide range of seemingly unimportant reasons, including a 4-inch crack in the exterior hull of the ship, the failure of several engine cut-off sensors, and what has been described as “the smallest of possible thunderstorms.”

I didn’t see it, but I understand that the original version actually called out John Shannon by name, but they later changed it to “Wilkins,” perhaps after complaints from PAO (or maybe John himself, though I imagine he’d have a sense of humor about it).

There actually is a grain of truth to this (though not, as far as I know, with John Shannon). I thought that they delayed a launch (that I attended) needlessly a couple years ago (under the Wayne Hale regime), and I have a more extensive discussion of that particular issue here. But as far as I know, John is doing a good job of balancing safety and cost/schedule.