Being an immigrant is not virtuous in and of itself. How many of those 40% 'immigrant families' immigrated here poor and climbed the economic ladder, and how many took stolen wealth from a feudal system in the old country and built a business?
Instead of investing in our domestic population with job training and scholarships, corporations are importing labor from overseas. Those people getting imported have degrees (sometimes of dubious quality) paid for by socialist states, often work for 'staffing agencies' to circumvent benefits and PTO of the real company, have very little job mobility, are most often paid below-market rates.
It's basic economics. More labor means cheaper labor.
Why are Blacks and Hispanics underrepresented in Software development [1]? If you compare the overall employment figures to the overall demographics of the country, they're almost identical, but way, way off for software development. It's because the most vulnerable people in the US don't have access to jobs and education, and corporations have no incentive to train entry level workers when they can just import them.
> so the U.S. is really shooting itself in the foot (again).
In what manner? The US doesn't need every genius walking on planet earth to reside in the US.
EDIT: reference
1: https://www.bls.gov/cps/cpsaat11.htm