Who are the core that drive this massive, amazing ecosyssytem (yeah, please what's another word for ecosystem? Am I the only one tired of it to describe any system?). Here are some thoughts.
1. There are the leaders of the movement who often don't work full time it's for themselves or an employer that pays them to be them. A few examples of this group (I'm including both "free" and "open") would include Richard Stallman, Linus Torvalds, Bruce Perens, Eric S. Raymond, Tim O'Reilly, Larry Wall, Guido van Rossum, John Gilmore. That's obviously not a complete list.
2. There are the outstanding professional developers with passion for their FOSS projects. They always seem to work for themselves or always manage to find employers who encourage open source contributions.
3. There are developers who are learning or otherwise haven't yet started working full time.
4. The 1% (mentioned by several commenters) who have very busy lives but manage to contribute as much as they're able.
I may be off and I'm definitely over simplifying but I say thank god for all four groups and others. I feel gratitude every day.
Yes, the FOSS world is political and narrow at times, which is a shame but that's human beings anywhere you find them.