Bad move from Apple.

Classic instance of the sunken cost fallacy fallacy (not a typo). They prefer to cut their losses and forget about how much they spent recruiting those people.

Keeping them might seem wasteful on the short term, but such skilled workers could likely be made profitable in a big R&D powerhouse.

But the real cost is damaging their reputation among future candidates and current employees, and lowering their perceived value as an employer.

For the most skilled and efficient engineers, choosing to work for big tech is always a tradeoff, a company like Apple is usually very appealing for the most risk-averse.