Several things:

"I only write if I feel like it and on a subject I feel like writing about"

No argument there. The world doesn't need more 500 word articles someone got paid $3 to write. Playing to one's strengths is fairly straightforward, and work that's driven by passion tends to be of much higher quality.

"Yet psychologists and behavioural economists (these charlatans) seem to think that it is a disease that needs to be remedied and cured."

Procrastination has certainly hurt me more than it has ever helped. Perhaps I disagree with the author's implied argument that "nonaction" is the same thing or is similar to procrastination. Procrastination for me is something that makes it harder to do things I know ought to be done. "The doctor who refrains from operating on a back" made a choice and went off to do something else; procrastination would've been the doctor lazying around hours before the operating rather than preparing, or something to that effect (I'm not a doctor).

Anyway, just my take on it.