In poker the hands you lose the most money with are the worst hands. If that weren't true you'd fold the other hands instead of playing them. That should be intuitive. Folding = 0. You'd never play a hand where the EV was less than 0. You'd fold. As a result you lose the most with 72o & similar hands.
Fwiw this is a digression from the post, I think the author may have been suggesting you lose the most money in situations where you're caught with the second best hand. That's clearly true, if you're dealt KK preflop and an opponent AA, you clearly lose a lot of money. In investing if you find what looks like a great business but things turn against you, you'll lose a lot of money... I hope that was his point.. But as someone else indicated, this is just unlucky. You accept these consequences when you play the game.
Poker is a lot like baseball where the game has strikes. The strikes are the rake, you're forced to participate unlike in investing where you can wait indefinitely. There are a lot of similiarities with poker and investing but people can overreach with their comparisons..