The second-last paragraph makes a point I've seen touched on a few times but never fully developed: That the labor of software developers is an economic complement to code. When developers write code and release it for free, we are commoditizing our complements [1]. Operating systems, libraries, frameworks and the like increase the productivity of developers, so by making those widely available, the demand for developers is increased.

Calling open source a "labor movement" as the OP mentions is not far off, considering its effects on control of the means of production.

[1]http://www.joelonsoftware.com/articles/StrategyLetterV.html