The real problem that author doesn’t call out is that at the end of the day, the people in charge don’t get hurt from these irresponsible boom and bust hiring practices. These companies knew the growth wouldn’t last, nothing lasts forever. They all maintain control while the little people suffer. The dream is to become insulated from the economic storms like they are.
You are presupposing that boom and bust hiring is bad, and worse than a more steady state approach. If one assumes perfection is impossible, it seems you suggest erring on the side of perpetually under-hiring as opposed to ever over-hiring. Why is that better?
Because it doesn't create unnecessary suffering for the unfortunate people who find themselves out of a job because some executive over-allocated for a particular role or department. Fundamentally, we want people to still participate in the capitalist system and not reject it because they're constantly treated like cattle.