This seems to be a complex problem to solve. On one hand you don't want to lose access to the smartest minds, on the other you don't want your citizens to suffer from lower quality education because of it. But its also a very economic issue, in the sense that most foreign students pay handsomely to attend prestigious schools, so it makes short term economic sense to trade education for their wealth, meanwhile students at home must take on massive debt to compete economically to be of interest to the institutions.
I feel like this is more of an economic issue than an education issue at heart. I agree that in most cases the incoming talent is not undeniable, so there is little argument for favoring foreign students over domestic students besides an economic one. Somehow foreign students, universities acting as corporations, and global trade has created the mess of the current education system which includes our whole student loan fiasco which makes the younger generation quit before they even start. It seems that colleges have lost sight of being primarily a system to educate the next generation.
Its a similar issue to american businesses taking their jobs overseas, but instead american colleges have, in some sense, taken their education overseas.