I don't think there is a misalignment of interest. Robust software is also correlated to the number of users. In my experience there is also no need to worry about not having enough open problems to work on. It could happen in theory I guess, but projects tend to have more open problems and feature wishes than developer time. If your software is used there will always be people asking for more features to work on. You don't get more projects because there are too many problems in your software which need fixing - you get more projects because your software is good and you are known to be the person to fix problems.