Just more wage cutting invaders.
This is the way it is done in Japan. I was their equivalent of an H-1B worker for 14 years. This restriction not only ensures no game playing but limits foreign workers to the cream of the crop or, IOW, makes the employer tell the truth about why they need foreign workers-- they are only willing to pay them more if they are actually worth more.
The locals tend to welcome it also.
More foreign workers = a higher wage level for the industry = more attraction to the locals to get the necessary training to work there = a long-run lesser need for foreign workers.