First, there are a lot more programmers than there are companies, and programmers are not unionized, so presenting a united front will be difficult if not impossible.

Besides, programmers want all sorts of different things. Plenty of us are happy to work for less pay at startups regardless of the equity situation, and the reasons vary: maybe it's a big step up from their last job, or the location is great, or they like small startup environments more than BigCo, or they didn't get the job at BigCo, or they're trying to build up a specific skillset, etc. It's not at all clear that common vs preferred shares is the hill that most of us would choose to die on.