This attitude is what allows any operating system to be usable. Nobody would want to develop code under Windows (or buy that code) if they knew that it would br

This attitude is what allows any operating system to be usable. Nobody would want to develop code under Windows (or buy that code) if they knew that it would break when the user moved from Windows 7 to Windows 10. In the IBM mainframe world, people can still run code written in the 1960s (without even recompiling it). If Linus didn't fanatically enforce backward compatibility, nobody could rely on Linux for mission-critical systems.