How is OSX a closed system in this particular case? You can easily compile bash, with patches, and replace the system binary -- using the same code that's used

How is OSX a closed system in this particular case? You can easily compile bash, with patches, and replace the system binary -- using the same code that's used to build those Debian/Redhat/whatever binary. Its all the same gnu code. What about all those EOLed distros that don't see most security updates? Being "Open" is a non-issue here.