The passage you quoted is pretty much the same argument that gets thrown around whenever professional athletes go on strike. Yes, they are already very highly paid, but in the end they have essentially "earned" it by any reasonable definition of the word.
As with the professional athlete situation, sometimes the only way to stop salaries from being artificially suppressed is to band together to stop it. This is what the recent class-action lawsuit against Apple, Google, and other big companies is about. If things get really bad, programmers may have to form a union or a guild to continue getting paid anything close to what they are worth. Forming such an organization will no doubt be very difficult due to the fact that many programmers exhibit a strong (and in many cases, misguided) belief in their own rugged individualism and in Silicon Valley's meritocracy. This belief wrongly leads some programmers to conclude that they don't need to protect themselves, thus leaving them open to collusion from their employers.
For a cautionary tale about what happens when people miss out on the chance to organize when they really should, look no further than the Hollywood visual effects industry. They are the only major aspect of feature film production without organized labor, and consequently their work is routinely underpriced to the point of VFX studios going out of business as a matter of course during a film's production. The same thing could easily happen to typical Silicon Valley programming work. (In fact, it's already quite close to that situation when it comes to programming in the games industry.)