I believe that every programmer is overpaid relative to the difficulty of the work they do -- or, more accurately, that The Market doesn't pay based on difficulty of work. Software pays so well because the product scales so well.
Successful pop musicians don't do work that's 100 times more 'difficult' than software engineering. They do work that scales even better (copying digital music; playing to arenas; branding on merch).
Having worked outside the software world, I absolutely do not believe that software people are any smarter, on average, than anyone else. Ever see a plumbing or electrical or structural system fail spectacularly? Other types of workers absolutely need to understand interactions between multiple complex systems, deal with obsolete and incompatible systems, and deal with changing and conflicting requirements and regulations.
If software is any more complex to deal with than physical systems, it's only because the architects and implementors let it get that way.