Half of it was a long tangent about NPD after which he flatly admits that his readers shouldn't be trying to diagnose NPD... but he's giving you detailed recommendations about how to recognize all the behaviors associated with it and then act on them! This is coming from a clinical psychologist, so that seems wrong.
I agree you want to identify people with that behavioral profile and get them out of your organization (whereupon they'll be Somebody Else's Problem...) but it seems like this psychology could be translated into guidance with less ethical sharp edges than "here's the DSM description of this disorder. But don't actually play psychologist, LOL!"
After that he finally gets to deadlines and kinda sorta gets into why they're bad. And I don't disagree, but the article claims that deadlines are used by emotionally immature managers acting out of "fear." Sometimes, but deadlines are way too commonly used in every sector of industry to attribute them to emotionally immature leaders.
It's off to a vignette about a manager who couldn't recognize his greatness. So after he's spent pages tell us about how narcissistic people behave, this section felt like he was trolling me to think he's a narcissist. (I don't think he's a narcissist, just full of himself; which may well be an accurate self-assessment.)
But the manager's problem wasn't deadlines, it was micro-management which manifests exactly as he describes. In micro-management deadlines are one of a number of symptoms, but the underlying problem is the fear and emotional immaturyity he mentioned earlier.
He finally does get to why deadlines are so common: "They are a form of contract that can enable multiple organizations to synchronize their efforts, organizations that might be in the same company or in different companies."
The need to synchronize between organizations is plainly why deadlines are extremely common.
That's my real criticism of the article: he's a clinical psychologist, a rather irresponsible one, and he's viewing this through that lens. While it's insightful in many ways, deadlines represent a structural problem more than a human problem and the article would be better if it didn't try to solve them. (And, in fairness, most of it doesn't even address them.)