We are also importing STEM workers when we should be hiring our own college graduates. This actual practice started back in the 80's when I was managing teams across the country for a large consulting firm. They would scoop up H1b visas so they could hire cheap foreign labor and then rent them at American wage levels Huge instant profit. Ran to at least $30 per hour per worker. At the time, US people were being paid $25 per hour and the client was paying $80. The US people were also getting benefits so their fully burdened rate was closer to $40 per hour. The H1b's were being paid ~ $10 with NO benefits. And that was 5 times what they were earning at home so they were happy. They were here temporarily and were living 4 to an apartment to save on expenses and sending as much as they could home.
Certainly not illegal but far from fair to American workers especially since the H1b law specifically prohibited undercutting American wages. My company's practice was to place very specific job requirement ads in local papers for $10 per hour. We got no takers so we filled the slots with H1b visa holders. This practice still continues to this day if you were wondering. Congress gives benefits to big business at the expense of the American worker.