I'm a rage-joiner
You know the net.phrase: "rage quit", of course. Well, I just realized that I often "rage join". By that, I mean, the whole reason I do anything with Free Software is because I'm furious about how badly proprietary software treats users.
Many of my major projects I've done have been because I was furious someone else was doing something similar from the opposition (i.e., in proprietary software, etc.) NPO Accounting, for example, I'm making slow progress on that, but when I make progress, it's because I'm furious that Blackbaud treats non-profits so bad.
I heard the "If you aren't outraged, you aren't paying attention" quote early in my activist life (as a teenager marching against war). It's stuck with me. I'm usually outraged about something, and I've learned to channel it into productive work for the cause. So, I "rage join". :)