I think that is a policy that should be very limited. In the long term, we do ourselves no favors by importing educated foreigners who reduce the need for educating Americans, which, in turn, enables the colleges and universities to continue being leftist madrassas. Another aspect of this is that by facilitating the brain drain from developing countries, we perpetuate the circumstances that make them third world cesspools because no intelligent people are left to work to improve those countries. As a result, people continue to have very high birth rates in those countries and there are no economic opportunities; the conditions that fuel the invasion of illegals into first world countries do not change.
Good points. Many educated foreigners make their entry into the US via university education. Graduate school in the US, even at lower ranked colleges is seen as a resume enhancer back at their home country. In my graduate school days, a few classmates returned home, but the majority used it as a springboard to stay here. Also, it may have changed since those days, but my faculty were very eager to have US grad students - getting grants and funding was no problem for us if we could make the grade - not a lot of money, but enough to live on, attend grad school and have some spare change.