I would assume that they wont submit
because they can find more fulfilling work elsewhere.
Again, I don't think he is addressing people who already have a job. Think about why he was even asked this question: apparently because there is this popular notion that America does not have enough IT workers and therefore needs to get 'em from India etc.I am not sure how true or untrue that notion is. But it is widely accepted.
I do see your point and think it is valid: the current American compsci grads and engineers usually can find a job. What this guy should be talking about is EXPANDING the total size of the engineering/compsci grads so even folks not necessarily very inclined can come in and do tedious but decent paying jobs. The end result is more money goes to Americans and fewer importation of labor from India etc.