They get pulled away by the lure of money into an environment that causes them to stagnate in their skill and career development, then companies pull the rug after only a few years of this high pay with layoffs. Now you've got hoards of developers with junior/mid skills who expect senior salaries and can't find jobs. Amazon doesn't want them anymore, because the new grad pipeline has plenty of people nearly as technically capable and much hungrier.

Only those who manage to recognize this short term period of plenty and rapidly stack investments toward financial independence will be alright in the end. Those who thought the raining cash would never end are in for a world of hurt.

On the bright side for Amazon, they get to trim off the employees who a) aren't paranoid enough about the viciousness of the business world, and b) are looking for a way to cruise and do minimal work.