that is changing. many of them are going home now (especially the Chinese). the only reason they came here is because the educational infrastructure doesn't exist in their countries. that is changing, they are building up in that area, and won't need US higher education after a while. the more engineers and scientists who work offshore, the larger the pool they have for some of those wokers to then take teaching positions - training their next generation in their own country.
give it time, the Chinese and the Indians know what they are doing. ask yourself this, if these tech industries are really "buggywhip", why is China and India so desperate to capture them? are they stupid?
Why are they going home if they can only work for $7.00/hour? One cannot simultaneously claim that it's not worth getting an engineering degree because it's too expensive with respect to the prevailing wage for engineers overseas, and also claim that students are coming from overseas and getting their expensive degrees and then returning home. One or the other.