Believe it or not, Amazon is not a charity. I don't know why you expect them to hold on to employees who are evidently a loss to their bottom line.
I am convinced they have zero data indicating firing these people will be profitable on the long run, only that short term it is, and that’s all that shareholders are interested in.
I’m a big fan of any measure making stock exchange less volatile, like some form of tax on every transaction, to slow down the machine, make short term investments (speculation) less rewarding. This may help in reducing the appetite of shareholders for such short sighted measures.
Should a company prioritise shareholder happiness over efficiency is the real question here. Their losses don’t originate from these employees nor initiatives; it originates from market conditions.