If you have a cause, and truly believe in it as an end, you have to be persuasive to the undecided—those taking the middle ground—not just those who already agree with you. I want people to be passionate about their beliefs. I want world-changing ideas to get a wider audience.
I can't claim to be able to offer any good advice, except to keep talking about it. Nobody pays me either, so I'm in a similar position! And the other side is, if you're not still enjoying working on a FOSS project, then stop and focus on the most important things. :)