What Free Software always was is an ethical movement—one which didn't need to prioritize income streams because the point wasn't sustainable development, it was user freedom. Nowhere in "users should have the freedom to do what they want with software" does it say "and we should be able to pay a few developers a salary for their work towards that fundamentally ethical goal". Under the original paradigm and goals, any income streams are just cream on top of doing the right thing.
According to the OSI's history of itself [0], at some point people got it into their heads that the open development model was inherently a good one for business, too—Netscape jumped on board, and then some people got together and decided to rebrand Free Software:
> The conferees decided it was time to dump the moralizing and confrontational attitude that had been associated with "free software" in the past and sell the idea strictly on the same pragmatic, business-case grounds that had motivated Netscape. They brainstormed about tactics and a new label. "Open source", contributed by Chris Peterson, was the best thing they came up with.
The word FOSS reminds me a lot of American corporate Buddhism—mindfulness and meditation totally removed from its original deeply religious context and turned into some sort of self-help program, with the result being something that would be barely recognizable to the original practitioners. Free Software was never about sustainable development. It was about doing the right thing—enabling user freedom—because it is right. Everything else was just means to that end, but at some point along the line the means became the end and we started wondering why FOSS wasn't paying the bills like it was supposed to.
[0] http://web.archive.org/web/20071115150105/https://opensource...