That's completely different from what he's talking about in the second half, which is the focus on financial markets. He's advising that people who don't know how to hedge themselves should stay out of the financial markets. He didn't specifically say it, but I think the rationale for that perspective is that the risk taking in the financial markets takes a very different form than the risk that an entrepreneur faces; the risk taking in financial markets can fail spectacularly and cause a lot more problems than bankrupting a single person. The best example is the LTCM crisis, where a single company's failure was so impactful and sudden that it threatened destabilizing the entire market.
Why is he so popular? And how did he get so rich on Wall Street if he just thinks randomness blows all the statistical experts out of the water? I know I'm missing something.
As a strategy, this depends on a rough prediction of when the next crash will occur.
If you think the tails are mispriced (and you have some kind of alternative distribution), and markets are liquid, can't you just keep on making Kelly bets? Maybe you need to model third-party investors bailing too, though...
However, Nature and more specifically economic events have little asymptotics in them (mainly isolated things like crises, earthquakes, crashes, accidents...).
I tend to agree with him on this.
He is not against science. He is mostly against economic modellers.