(Again, working within the normative framework suggesting immigration should be restricted, which is not my view.)

I can't say, as I didn't write the laws. My guess is that US immigration law is designed to limit skilled immigration because educated Americans in white collar jobs can raise a bigger stink politically about H1B competition in high-wage industries than working class Americans can.

As a foreign student who completed his undergrad education in the US, my student visa interview required me to show evidence that I would not try to use the F1 student visa to transition to H1B or a different visa class that can be linked to a green card application down the line. This is standard policy, as my friends who're also US-educated had the same questions during their interview.

It's also difficult to enforce because once you're in the country and have completed your education, you can be recruited by a company who will sponsor your H1B, at which point the ICE will evaluate it as they would any other H1B application. So the whole rigmarole seems pointless to me, but that is bureaucracy for you.

I feel like you are implicitly appealing to a very extreme version of the Copenhagen interpretation of ethics: http://blog.jaibot.com/the-copenhagen-interpretation-of-ethi...

There are many methods, one common one being to lie about how many weeks pregnant the woman is (note, for example, the woman who gave birth en route on a flight that had to be diverted to Alaska last October).