Trust me the people who spent all their time focused on the GRE don't make it to decent grad programs.
The elephant in the room isn't why aren't more universities accepting 'local' students. No department would choose a foreigner over a local. You wanna know why? How much the student is going to cost them. Foreign students never qualify for in-state tuition (well at a state school anyways) and right off the bat are much more expensive to their advisor's budget. Local students can also apply for NSF Graduate Fellowship, and bring in their own funding, something most foreign students can't. Both of these factors make it so that the first preference is to hire local.
That said, in a large number of departments (especially in CS, and other sciences) you see a burgeoning international student population. Why? There just weren't enough decent local applicants to go around and science needs its foot-soldiers.
The elephant in the room isn't why aren't more universities accepting 'local' students. No department would choose a foreigner over a local. You wanna know why? How much the student is going to cost them. Foreign students never qualify for in-state tuition (well at a state school anyways) and right off the bat are much more expensive to their advisor's budget. Local students can also apply for NSF Graduate Fellowship, and bring in their own funding, something most foreign students can't. Both of these factors make it so that the first preference is to hire local.
That said, in a large number of departments (especially in CS, and other sciences) you see a burgeoning international student population. Why? There just weren't enough decent local applicants to go around and science needs its foot-soldiers.