Makes sense, I agree with you and your assessments. Except for the last point, maybe. Seems like it'd be a weighing of effort and use, or maybe someone implements it out of technical interest. As a feature, I think integrated bug reporting is a good thing. It reduces various barriers. No need for the user to know or learn about and register with whatever tracker the project uses, etc. Still, depends on the project, kind of users, and certainly effort. If implemented it has a maintenance cost and potential for bugs too.