Lawyers and financial traders, maybe. Doctors, not so much (at least in the US). The NRMP is a far more effective wage-fixing cabal than anything anyone in silicon valley could ever dream up, and it's 100% legal.

> Software engineer's salary is nothing compared to doctors, lawyers and financial traders who enjoy protections from their organizations and a reputation of "being just expensive".

Not really all that true, for the professions as a whole, except for medical doctors, who are far above any of the others.

Per the BLS Occupational Outlook Handbook [1], 2012 Median salaries for various professions:

Securities, Commodities, and Financial Services Sales Agents: $71,720

Software developers: $93,350

Lawyers: $113,530

Physicians & Surgeons: >$187,200

[1] http://www.bls.gov/ooh/

In the valley I think I'd rather be a software engineer than a doctor or lawyer if I wanted to maximize my expected career earnings.

I should point out that your Expected career earnings has nothing to do with your profession and everything to do with what you actually do.