Why are you assuming that money is their only incentive?

It seems to me that if the promise of a golden parachute led to CEOs simply not caring if they do well or not, then there'd be no point in paying them well or trying to hire the best. Heck, there'd be no measure of "best", because all the candidates would just have a string of disasters behind them.

There's an S curve to the utility of money. Anyone who works at the kind of level that could become the CEO of a company like Boeing is already quite rich. So money alone isn't the incentive. But thinking of money as sole incentive is kind of characteristic for those of us who actually have to work for a living.