Because that would lead to an influx of an infinite number of people from a particular south asian country.
They have to get accepted into a program and graduate and they have to have the funds to pay tuition. Then they'll work productively here and pay taxes. I can't think of any reason why this would be a bad thing except the bigoted "ugh, too many Indian people."
Absorbing educated people from other nations is an economic superpower.
More educated immigrants lead to more jobs and economic growth.
1. https://www.cato.org/blog/fiscal-impact-immigration-united-s...
2. https://www.aclu.org/other/immigrants-and-economy
3. https://www.bushcenter.org/catalyst/north-american-century/b...
4. https://budgetmodel.wharton.upenn.edu/issues/2016/1/27/the-e...
5. https://www.cbpp.org/research/poverty-and-inequality/immigra...