This is true, but it is not possible to solve every problem you come across; sometimes the most you have time to do to help is to provide feedback. It is also much more efficient for someone who already has experience and familiarity with the codebase to make the change. "Do it yourself" should not be the first option taken.

For example, after learning from experienced people in this thread, I now know that if I had tried to implement this change myself, it would either be rejected or I would have wasted an hour or two of research finding out why it would be rejected-- apparently this program's plugin system has plugins make new desktop files, so it's done this way for plugin support. An experienced maintainer of this project would know that and avoid wasting time on a change (or have the social authority to make the choice to move to a different desktop file system for plugins).