"If a company is losing money from employing an engineer at a below-market rate, that means the company likely has a bad business model, not that the engineer is paid more than they're worth."
I need to call BS. Just because your business model can't justify paying engineers two years out of college a $120,000/year salary doesn't mean that you don't have a profitable business. It's okay if your business model isn't as profitable as Google's. Heck, a lot of the companies that are paying market salaries have no meaningful revenue o even a business model. They're investor-subsidized.
"employees should go work in environments that maximize their value."
A lot of people work in "environments that maximize their value" and they're miserable. I have friends who make half of what they could make in SF/SV. You would say that their current employers aren't maximizing their value, but most of them own their own homes, live very comfortably and are home by 5-5:30. I don't know many $120,000/year+ engineers in SF/SV who can say that.
A lot of the high-paying jobs in SF/SV that are compensating employees at their highest theoretical value aren't as glamorous as the people who have caught the grass-is-greener-bug would like to believe they are. A lot of the people in these jobs trade whining about salary to whining about the hours, the lack of interesting work, their crazy/incompetent boss, the fear of funding running out, etc. etc. etc. Pick your poison wisely.