I'm not really a contributor to Hercules (or any RO emulator for that matter), but I've contributed to opensource projects before. You can't really expect any kind of appreciation/feedback for your job. But this is not the "problem" I see in projects like this one.
The problem, for me, is when the project is making money to a lot of people who couldn't really care less for the project itself. The last project I contributed to, the users started to turn the thing into a cash making machine. They'd only hang out in the forums to request new features or support. As soon as they got what they wanted. Poof. They'd vanish. So you'd have a community with a lot of users, a great deal of them making some cash with the software, and no one really giving anything back. Be it support on the forums, documentation or helping out with the bills. The guy responsible for hosting the support forum would pay for the whole thing by himself.
And that's where I draw the line. I'm cool with spending some of my free time to contribute to a software that I enjoy even if I don't get any feedback, just helping out is fun for me. But when my contributions are helping out a toxic community, I feel way less inclined to help it at all.