Apart from being open source what is Linux? Could I not create my own operating system that is different to windows or Macos and call it Steve, again there might be an awnser for this and sounds stupid but its more out of curiosity.
Just a little addition: the majority of things that people associate with Linux as per your first item are actually shared by many/most Unix-like OS and are defined via the various POSIX standards.
That’s not to say that Linux doesn’t have it’s own peculiarities, but they are fewer than many people think.
They do - and in some cases you can fit both items to a T, without fitting the “hard” requirement (Linux kernel); that was the case with Debian/kFreeBSD for example. (And even “vanilla” *BSDs feel right at home for most Linux users, I think.)
