I've never heard this argument, but it honestly sounds extreme. We are going to force people to leave because other countries need good citizens? And you think that is the US government's rationale?
Do you have a source?
I absolutely think that lots of these people would only be able to achieve their goals in America, and their home countries could not come close to what America can offer them. On top of that, the brain drain issue in other countries is not going to be solved, or even close to that, with the small number of people that get rejected h1b's each year. It honestly sounds out of place that we don't let people themselves decide what would give them the greatest happiness.
As a small side comment: What about people who are legitimately scared about going back to their country, because of conflict or their sexuality being unaccepted or the like? All of these people are in the same bucket currently, from what I understand. Is it greedy of America to offer them an opportunity here, or is it more important that we are giving them shelter away from their country?