More rational countries help their people to get access to college without getting eternal debts, so they nation does not need skillful workforce from other countries.
Actually, the United States benefit much from people with college education moving there without their banks and taxpayers to have invested in those people by educating them at all.
Just think about the amount of money governments from developing countries spend in their students so they can graduate and help the country to develop technology and push forwards, and instead an important percentage of them immigrate after completing their studies. Brain drain is one of the most revelant social phenomena which the USA has taken advantage of, being the most classical example of it Albert Einstein.