Rationale is that they are now competing on a more global market, increasing labour supply. Which is true in a sense, but I imagine their dream is they don't have to pay silicon valley developers as much, but the pretense there was already that they were at the top of their field and their relocation and visa costs were covered. Certainly the ones working at Google, Facebook, et al. earn their salary more for the sake of not working for a company that could in any way threaten the near monopoly powers of the big tech firms. It's probably going to disproportionately hit more working class office jobs which the market is saturated with applicants, but most applicants come in with a lower bar of literal survival the employer had to meet, so secretaries, HR people, (maybe?) bookkeepers, and others who are "lower" skill but important to the functioning of an office.