There is no reason why we should send a freshly graduated physics scientist back to Uganda or whatever because he can't find an employer willing to pay him/her some abstract 130k salary straight out of school (which is A LOT OF MONEY).
Again, when I hire - I do it strictly based on skills and experience. If I have to do a bit more paper work to get this talented guy work for us I'll do it - but there is a limit. And at 130k limit a lot of these brains will flow back overseas. It would be a huge mistake for USA to get rid of willing to work just talent like that.