I believe that was the evidence provided by the great outsourcing experiment of 1996-2006. Turns out programming can't easily be turned into a low-skill job.
I agree. So why have so many programmers in Silicon Valley? Why don’t they leave and demand independent contracts? Perhaps that kind of “unbundling” of technical talent is the future.
It's the problem of being paid enough. My wife asked me the same question recently, "Why don't programmers unionize?" They could demand more through collective action, but they don't feel the need.
Also, programmers are (often) worth more in teams. Two programmers who work well together are far more productive as a pair than the sum of what they'd do in isolation.