* Early startup employees have golden handcuffs regarding switching jobs. Sure, Facebook is offering them $500k but they'd be on the hook for $200k in taxes if they exercise their options and they leave a bunch more un-vested options on the table.
* You can mitigate them leaving by having a better work environment, equity and so on. Not much you can do about a bus.
* You can pay them to stay on for another month or to consult after the fact. No amount of money get's you an hour long phone call to the afterlife.
edit: Also, the article underestimates the effort needed to get a FAANG job. They don't just call you up and offer you a job. They offer you the chance to take a grueling set of white board interviews that require months of studying to pass.