> If they exclusively work on open source stuff where are they getting money from to survive?

These are orthogonal. One can have a paid job while contributing to open source for entirely altruistic reasons.

> Follow the money trail… even a donation… eventually it leads to an incentive based source or action.

BS. Humans do things for altruistic reasons devoid of individual reward all the time.

I, myself, maintain multiple OSS projects entirely for fun and with the hope that others will find it useful. That's it, that's all. I also donate entirely anonymously to charities simply because I believe others deserve support and dignity.

This form of cold, American libertarianism you espouse is pure poison in the body politic, both in this US and globally. It degrades all of human interaction to transactions. Its no wonder that the US is where sociopaths like Zuck were birthed.