These sort of method(s) being used and deployed by the American border agents are sanctioned and pushed by the U.S. government from both parties.
It's done to ensure as part of American effort on cognitive warfare or psychological warfare as part of its overall effort to isolate these talented and bright Chinese academics and others from their country and to blame their country's political leaders and ultimately system as the source of all these negative treatments they're experiencing. The action and even the assumptions being made by the powers that be like Pottinger and his ilk assumes that these same Chinese people will not hold the U.S. government and the country as a whole in general contempt and will be the one hold accountable by many in China and not just the CPC.
To many of the American anti-China hawks the experience of discrimination against Chinese national are just collateral and part of the necessary strategy to negate and arrest the advances China has been able to make these many decades. Apologies can be made and meal culpa will be issued when the American hegemon is all but assured. Otherwise, the fear of China surpassing America and every meaning of the word is not something they can or will be able to accept without causing untold destruction.
If enough talented Chinese people can be co-opted through this action and maybe even use them as potential spies and saboteurs for America against China that would be an optimal outcome but if that fiction does not materialize? Who gives a flying toss since that's not the main strategic objective and aims but only an ancillary benefit albeit with low probability.