I think the suggestion from the parent was that if you prevent i.e. Google from bringing in H1B workers, they will simply hire them in their India office.
The market may not be global from an employee point of view, but that's an oxymoron, that has never been the case ever in any field. ( not saying it is a good thing )
Without any protectionist measure, it just remove one of the many resourcing options for the large US companies. It is unrealistic to think that the job will be automatically reassigned in the US when those companies are already spread all around the world.
All I'm trying to say is that suppressing H-1B is probably good because abuse is never good. However, I don't believe it will magically solve the problems of stagnating salaries without something else.
But software services flow the other way. Google, Facebook, Microsoft etc. are big players in India, and US employees benefit from increased revenue and profit from those populations.
You cannot arbitrarily pick and choose the aspects of globalization that hurt you vs. that benefit you.
US employees of "Google, Facebook, Microsoft etc.", or US employees in aggregate?
These same people won't stay there if / when they decided to have children and educate them, though.
The tech worker market segment the body shops proliferate within in the US is one-way permeable: from developing to developed world markets. There is nowhere near the kind of market demand for developed world tech workers in developing world markets. Without that equivalency, claiming a "global" market omits key information, because everyone who makes that "global" claim is trying to advance the argument that the globalization status quo is a two-way street of equal opportunity, and US workers should therefore welcome this new normal. There is in actuality an arbitrage over standard of living, environmental conditions, rule of law, etc. that coupled with US immigration laws create the market opportunity. That arbitrage is an externality cost pushed onto US taxpayers.
When US economists for globalization move en masse to India for its obvious competitive advantages over the US cost of living, because it is so cheap to live like a local in India and an economist can "obviously" work from anywhere, then their academic prescriptions align with their personal creed, and I'm all-in on globalization again.