exactly, I believe this is still done. I'm just jumping into the middle of these threads and perhaps this has already been said but I believe that the H1-B program is all about importing cheap labor, period. In other words, reducing costs. In many areas programmers are in high demand, so much so that it is worth it for many programmers to constantly learn new skills to stay in the game. The H1-B is all about getting a steady supply of 3-5 year programmers at 50-75K rather than paying citizens 75-100K.
I'm not sure how the hefty requirements of the investor visa fits the Y Combinator model. It could create exploitation issues if not handled properly. One could imagine the investors putting the money up but that changes the dynamic of ownership. I believe the investor visa can be satisfied with job creation or money but then there's the issue of minimum wage laws, founders typically work at a loss since they own the company.
I've always felt our immigration law is absurd with respect to graduate students. I think a green card ought to be attached to an advanced degree so that these folks will stay here, enter the work force unencumbered in order to compete fully and start paying taxes immediately, raising families, etc.. Instead we try to keep them out whilst encouraging small businesses to hire illegal immigrants with poor skills thereby creating resentment over access to public services.
Sorry to rant, it's a touchy subject.