Exactly, we should only use flat files for configuration, and the /etc directory is not a single point of failure because reasons, and the file system is not a single point of failure because reasons.
And the cpu is not a single point of failure because reasons ...
You can always boot linux or bsd off another media and fix the problem - usually quite quickly, with nothing more than vim. Or in the case where the complete file system, or even the hard drive itself, are toast, just reinstall. Or even just use the computer for the next year or two without a hard drive - KNOPPIX is great for not needing a hard drive. A reinstall of windows is a real PITA in comparison.
Windows is a single point of failure. Product activation failed because you changed some hardware that died? Sux 2 B U. Can't activate the OS because it's no longer supported? Either find a crack or again, Sux 2 B U. Doesn't matter that you have a fully paid up license, and that in the case of XP, Microsoft promised to release the activation keys once they stopped supporting it. They lied.