This not about blue collar vs white colar. After all corporate programmers and web programmers can both be blue colar, and systems programmers can be white colar (if we're using "blue colar" to mean smaller salaries and fewer percs - otherwise programming is a white colar job anyway).

This is about how many work in kernels/embedded systems/etc vs more common programming gigs. And that's less about how many are trained to do so, but rather how many are needed.