Also, I would wonder: 1. How much of those foreign graduates went to college solely for a visa. 2. I would also expect that those graduates have much lower expectations from the life style. Young men don't really need a lot of money and have a lot of time to spend at work.
Go ahead and ask any immigrant who had a H-1B about their path. I am confident you will come to the same conclusion.
From my experience most h1s are imported by vendors. I've seen a lot of really small "consulting companies" who does this. I had heard over and over again that most regular companies are terrified of having to deal with H1s, due to extra cost and lots of uncertainty.
The H-1B program is heavily used by graduates from US institutions.
I would welcome someone actually studying this rigorously. I am confident my observations will hold. There is also no evidence to assume that Indian consulting services occupy the majority of H-1Bs.