Exactly. Many OSS developers work for free. Myself included (I develop some OSS software). And the way I try to be a good OSS citizen is by being constructive and supportive in various OSS communities I care about. You're not going to get my money. But you might get my time, attention, and skills. For free.
The way the OSS communities works is not money but value creation. There are all sorts of value people get out of creating things for each other. People like the recognition and appreciation they get for their work, the satisfaction they get out of doing a thing, the interactions with others, etc. Plenty of ways to get value from creating stuff for others. And sometimes people actually get paid directly or indirectly to work on a thing. It's fine. I'm not against that. Just don't expect/demand me to pay for a thing. And I won't do so either. That simple promise is why OSS works. We both end up getting some value if we work together. And we might even get paid indirectly. For example I have a consulting career and I dabble in startups. So my motives are not entirely altruistic.
The way the OSS communities works is not money but value creation. There are all sorts of value people get out of creating things for each other. People like the recognition and appreciation they get for their work, the satisfaction they get out of doing a thing, the interactions with others, etc. Plenty of ways to get value from creating stuff for others. And sometimes people actually get paid directly or indirectly to work on a thing. It's fine. I'm not against that. Just don't expect/demand me to pay for a thing. And I won't do so either. That simple promise is why OSS works. We both end up getting some value if we work together. And we might even get paid indirectly. For example I have a consulting career and I dabble in startups. So my motives are not entirely altruistic.