You do not demonstrate much knowledge of labor markets for university faculty. There are plenty of foreign professors in US universities. Universities can hire foreign professors. There are many foreign students who take faculty positions in US universities.
I am strongly in favor of driving down the cost of university education. I am surprised that no competitor has done it yet, especially in business and engineering. There seem to be some significant barriers to driving down education cost: accreditation, public perception, and large startup capital.
Tenure has been eroded somewhat but it remains strong. A number of legislatures have passed laws requiring post tenure review. However, post tenure review only removes the very poorest faculty. Tenure does not mean that your salary will grow. Unproductive faculty often are denied raises, given poor teaching assignments, and given high administrative duties. I knew one faculty member who had not received a raise in 20 years. I am not a defender of tenure or academic freedom. The taxpayer should have more power to ensure faculty productivity.
I have mixed feelings about tenure. I do believe it should not be handed out to those who have not demonstrated academic excellence. I wonder how many conservative college professors could get tenure these days?