The article says its unrealistic; not that its impossible.
Its unrealistic to tell every star High School athlete that they'll become the next million-dollar NFL player. But, its not impossible; in fact, they bring on million-dollar players every year. The point isn't that its impossible; its that its improbable.
Tangentially-addressed in the PS at the bottom:
> PS. My colleague Zefi Hennessy Holland raised an insightful point about hard to find market secrets that I can’t phrase better myself.
>
> He said ‘If Math Hard is finding the solution to a problem many people know about, Market Hard means finding an industry problem that few people know about through a lot of hard work… Your competition can copy your moves but not the underlying insights that made you make them.’
Uh... free for the taking is not exactly right. They patented the shit out of it. Look up the "Wright brothers patent war" they waged world wide for licensing fees. It took WW1, with the USA extremely far behind in aircraft innovation, for the gov to end their patent trolling adventure.
These gentlemen would beg to disagree:
https://en.wikipedia.org/wiki/Wright_brothers
Before the Wrights, numerous others had tried and failed to achieve what they achieved. Of course, once the Wrights succeeded (or rather, some time after) their idea was free for the taking. But the Wrights did have a "unique insight" that was only their own.