I would agree with you on the potential benefit of a lightweight union that existed only for specific purposes, e.g. negotiating health care or lobbying on my behalf. A traditional labor union would, IMO, entail too much bureaucratic inertia to be of much utility to anyone in the field.

Besides that, I have to ask how long this collective experience of programmers enjoying happy lives will last. My general observation is that the accepted value of that labor is cheapening rapidly, whether from scarcity of jobs, glut of available talent, or the general difficulties in remaining competitive when the skillset is often globally portable.

My friend who basically left his engineering field to make more money cleaning pools strikes me as a demonstrative example.