Importing non-U.S. citizen with High IQ's and/or strong backs is an American tradition. Think waves of indentured English citizens, waves of Irish, Scots and German citizens, waves of African (via Slavery) citizens, waves of Chinese citizens, waves of Eastern European citizens and todays more sophisticated pseudo-wave of non-U.S. citizens being imported from South America, Asia, Eurasia and Eastern Europe.
Those people that don't become American citizens after grad school, must not like it here or they wouldn't pass up the chance to stay here as citizens. I wouldn't want to force anyone to stay here that doesn't like our system. As for me, I love it here. I've traveled the world extensively and there's a lot I'd like to see improved in the U.S., but I never visited any place on the planet, including all the EU counties and the U.K., and none can top living in the U.S., even with all our warts and system flaws. By my standards, most are either too poor or too socialist or both.
We should not only "address" the bloated education bureaucracy and ineffective associated education policies that currently (mis)function at the grade and high school level...we should take positive action. But High IQ, ambitious foreigners aren't the ones to blame for the Education System in the U.S. The student visa'ed foreigners that I know, do their darnest to get green cards, and then work at process of staying here to became U.S. citizens.