Earlier quoted context omitted.
Not enough for what? Paying expenses? Or are you expecting that open source contributions are to be paid at developer rates, and that one should contribute only as much time as is adequately paid? I thought open source meant that everyone was volunteering by default, just writing the features they'd enjoy to have for themselves, and that sponsorship of development time is not the norm aside from hugely important proj…
Yes, I am expecting exactly that, many developers want to try to make a living from open source. GPL was never about doing charity.
Adopting GPL used to be a philosophical mindset consciously chosen (as opposed to freeware), and required some level of zealotry. Now, it's just a means to an end / pragmatics / a tool in the "growth hacking" toolbox because "everyone knows" having an open source project gives it an edge over closed-source equivalents on adoption.
IMO, it's not that open source developers have to earn a living (which they always have since the beginning), but that developers who want to earn a living in any way have started adopting open source by necessity. I'm no purist, regardless of motivation, the more open source projects there are, the better it is for everyone. For once the source is out: it is out.