I think all this applies only to developer tools/libraries. There interested people can also help i.e. they find a bug and fix it and if they are nice, they con

I think all this applies only to developer tools/libraries. There interested people can also help i.e. they find a bug and fix it and if they are nice, they contribute. Projects for end-users tend to either have a corporate interest behind them, are ex-commercial projects, have a strong core developer team without which the project will die or just live and die unnoticed. As in every project, if you think 90% is done actually less then 50% is done. Documentation, installers, etc. are all a lot of work. Try getting a new package into the major Linux distributions! If you do not have documentation, installers etc. you won't get users and your project will be irrelevant - if you are lucky someone contributes, but most often everybody has his own pet projects in which they are emotionally invested.