I'm not sure I follow your logic, but if it helps clear anything up, I did emphasize that this was an old story, like twice. I am also aware that Qt is GPL now, and that GIMP has hundreds of forks.
You are looking at the wrong number :) That's the total amount of forks on GitHub. Whereas only 15 of them had any commits by people who forked the repository. Among those 15 people:
- One is a regular GIMP contributor.
- One couldn't wait another day for a macOS build of version 2.10.12.
- One patched file association on Windows and submitted his patch to the upstream project.
- Some of the others worked on their pet peeves, and some of them discussed it on the upstream bug tracker.
You might want revisiting your definition of a fork :)