I'm pretty critical about the H1-B/L1 systems but my biggest problem with them are the restrictions they place on the visa-holders and the power they give the employer over the employee.

This affects me because I compete in a market where a substantial portion of my colleagues are modern-day indentured servants. This affects my working conditions, compensation and opportunities.

With respect to your point, I think it's valid but I don't think it's as simplistic as more local engineers == less pay. For one thing, we're already competing in a global environment -- software crosses borders easily. For another, the labor pool is never zero sum because more people consume more resources and demand labor. OTOH I don't think unilaterally throwing open American borders would work very well and I think the position of this article is naive and idealistic.