Here's what I think - while Altman was busy trying to convince the public the AGI was coming in the next two weeks, with vague tales that were equaly ominous and utopistic, he (and his fellow leaders) have been extremely busy at trying hard to turn OpenAI into a product company with some killer offerings, and from the article, it seems they were rather good and successful in that.

Considering the high stakes, money, and undoubtedly the ego involved, the writer might have acquired a few bruises along the way, or might have lost out on some political in fights (remember how they mentioned they built multiple Codex prototypes, it must've sucked to see some other people's version chosen instead of your own).

Another possible explanation is that the writer's just had enough - enough money to last a lifetime, just started a family, made his mark on the world, and was no longer compelled (or have been able to) keep up with methed-up fresh college grads.