Developing software and managing a community are totally different skills and mastering both is not to be taken for granted.

Plus, since you are very passionate about the open source projects you maintain or contribute to, it is difficult to "detach" yourself from people's issues and not feel every criticism as a personal attack (and yes, when your software does not have the features/behavior they expect, some people can express their disappointment in quite a sharp way).

I prefer not to make anyone pay anything but "you get what it is, be warned that you may experience some bugs or lack of support for certain devices" (because I can't buy every piece of hardware and test). Few people have accepted this model but, those who did, have always been supportive and respectful, making me rediscover a little hope that kindness isn't dead at all.