So the problem isn't the immigration restriction, it's the lack of screening. Using PG's logic, all of those 100,000 should be 'exceptional' or else we're wasting tens of thousands of visa slots that should be going to the 'exceptional.' And how is 'exceptional' determined? We should let everyone in with the hope that some percentage happens to be exceptional? What about the non exceptional? What would that do to the overall quality of coding if you 'dump' 95,000 unexceptional programmers with the intent of harvesting 5,000 exceptional ones. Is it fair to suggest that the Infosys recruiters aren't hiring 'exceptional' but lower cost? I get recruiter emails all the time; several per day, yet never once have I received an email from Accenture, Infosys or any similar company known for hiring lots or foreign workers. So interesting that their shortage obviously isn't such that they'd resort to bugging me. Of course, maybe my years of experience and companies I worked for would indicate that that I would not be as cheap as the thousands they bring over from India. Nor would I put up with being locked into a position as an effective indentured servant. So many it isn't that there's a shortage of engineers but a shortage of ones that are willing to work under conditions common to those who desire to import more labor. Facebook doesn't necessarily want to hire more imported devs, but an increase of supply would allow them to have a larger talent pool at a lower cost. Of course, this discussion is a bit old school..
With remote working, geography is somewhat irrelevant. Perhaps instead if changing immigration instead PG promoted companies embracing a remote culture -- then you could have the best of the best with minimal beareaucratic entanglements. After all, given that, according to PG, it's about 'exceptional' talent, working remotely shouldn't require the same level of management overhead as would a lower quality dev 'sweatshop.' However the fact that isn't even being discussed makes one believe that this isn't about finding 'exceptional' talent as much as it's about lowering the scarcity of developers willing to work for lower wages than they might have received otherwise.
Under the PG logic, we ought to simply open the floodgates to all people, because inevitably from the multitudes there's bound to be a few geniuses. But, does the cost of those geniuses outweigh the costs to everyone else? Should we strip mine the Rocky Mountains to find an ounce of gold?
I don't know the answer to the question and I am not advocating either way, however when a company like Facebook begins asking for something, I question the motives -- I don't think Facebook has a talent shortage at all, they have a desire to pay less for their inputs. Which is a fair desire; however we shouldn't just blindly allow policy decisions to happen just because some tech 'leaders' ask for it. It is and always has been about the bottom line.