It's a disservice to the brilliant visa holders I know as well as US citizens. it's extremely hard for them to get a job at a good company because so many of the visas are getting soaked up by those abusing the system.
If there was a huge engineer shortage you would see companies step in to provide developer training problems. This is clearly not happening.
What I'm disputing is this notion that there's no shortage of qualified developers. There absolutely is—that's why you see substantial salary growth for senior engineers.
What exactly do you think bootcamps are? They're outsourced developer training programs whose entire business model depends on the high tech salaries.