If you want to play salary comparison, here's another one: the bus drivers in my town earns about $50K/year. I know a lot of programmers who makes a lot less than that. To top it off, they go on strike about every year because they want more.
What about nursery workers who makes about half what the bus driver earns? They have great responsabilities, lot of stress and need higher education than a bus driver.
We can find a lot of exemples of injustice in the market, not only in the computer business. Few are getting what they are really worth.