The vasy majority of my contributions are in no way proprietary and have no real use for me in a proprietary setting. Some other stuff does.
And yea, it is doing its job by cutting off developers from wanting to contribute to it, which is why copyleft has been dying out significantly in recent years and largely replaced with MIT and apache licenses.
The trend of GPL to isolate itself and push developers away by punishing the very people who release under it is exactly why its dying.