I disagree - I think that people usually do know how they could be more productive. This argument is really about people who TALK versus people who DO - the talkers know that optimally they should be "do"ing. But, being a sheep (talker) is BORING, and being a fox (do-er) is LONELY.
In the author's example, the comedian knows that watching re-runs is the easy way out. He'll be bored, but he'll learn a little bit and he can tell his friends he's working.
He also knows that, ideally, he'd be working comedy all the time instead. But he's already working another job, he's tired at night, and if he REALLY plunged into comedy he'd lose his free time too. He'd be lonely and on his own.
This isn't an issue of the comedian not having "strategic" capabilities. It's an issue of him not being a risk-taker, not being sufficiently motivated, and in many ways of him just being tired out!