Playstation OS is based on FreeBSD, there is nothing to upstream into Linux.
If you want to talk GNU/Linux, then we can switch to Android and ChromeOS, which have indeed done several contributions, in fact many of those left out weren't accepted.
So, as you can see, there's nothing to gain from GPL in this scenario: the choice is between Sony not upstreaming their changes because they don't want to (BSD), or not upstreaming their changes because they couldn't use your code in the first place (GPL).
With Android, Google wanted to give their changes back, so they were able to use GPL-ed code. They would give the changes back without GPL too. You can see that with non-GPL-ed projects they contribute to.
Nope, you are missing the whole picture in order to frame your argumentation.
Several Google contributions were taken, just not 100%.
One notable contribution was cleaning up the kernel from all VLAs, the fortifications of several modules, some cleaning outcomes from clang compilation support.
You're stopping your reasoning at the numbers: some contributions from Google, none from Sony. (At this step you're also ignoring contributions to FreeBSD from companies that do contribute back, but whatever.) The big picture would be understanding why GPL wouldn't affect that situation.
I feel like this isn't really framing the issue fairly. The issue isn't that Sony couldn't use GPL code, there is no law preventing them from doing so, they just choose not to (for a variety of reasons, I'd imagine). Just as the could contribute to FreeBSD but choose not to.
And OS developers have the choice to prevent Sony (or some other company) from essentially using free labor to make money without any obligation on their side.
Of course, but they can't just copy&paste their favorite files from the linux kernel sources and call it FancyOs without releasing the sources to that.
I think you got my point, I don't really see the benefit in arguing semantics.
It’s not about semantics - it’s about demonstrating that Sony using someone’s sources doesn’t hurt that someone, and trying force them to give away their changes with license doesn’t work.
They didn’t necessarily choose FreeBSD because of licensing. Perhaps if FreeBSD has more restrictive licensing they would have still chosen it and had to upstream changes.
If you want to talk GNU/Linux, then we can switch to Android and ChromeOS, which have indeed done several contributions, in fact many of those left out weren't accepted.