> That's the spirit here
not really.
All this Free Software movement started by something really similar to "right to repair", a firmware bug in a printer that was proprietary software.
Free Software is about being in control of software you use. The spirit was never "contribute back to GNU", the spirit was always "if you take GNU software, you can't make it non-free". Those GNU devs at the time just wanted a good and actually free/libre OS, that would remain free no matter who distributed it.
You are using expectations of modern day devs in the world of a lot of social development thanks to Github.
You might claim that GP was using the technicalities of the licences, but you can actually check the whole FSF philosophy an you note that they align perfectly with "giving forward" not "giving back".
Free Software is about user's freedom. Not dev rights, or politeness, etc.
Now obviously, some devs picked up copyleft licenses with the purpose of improving their own software from downstream changes (Linus states that is the reason he picked GPL), but that's a nice side effect, not the purpose. Which ofc, with popular social sharing platforms like github, those things gets confused.