back to the comments above: the management knows not the people who do the actual work. They can't immediately tell if the Chris who left was carrying his team or was the worst slacker in the company. They'll learn after they audit the remaining workforce and see The Spreadsheet say the people who remained are bottom performers (pun probably intended) but it'll be too late - the talent is gone, the trust is broken. Whether different companies learn from each others' mistakes is a mystery to me, apparently the global conspiracy of billionaire CEOs is not as robust as I expected (/s)