Many old desktop operating systems (and some recent hobbyish ones, like AROS) don't use x86 memory protection. Which leads me to a slightly ridiculous idea: Desktops need security, data integrity, and performance. They do also have to be stable, but only enough to maintain data integrity and be consistently usable. Long uptimes are not necessary. What if, instead of designing OSes that leverage memory protection to mitigate memory exploits, one designed an OS that avoided using memory protection with the intent of failing as quickly as possible, i.e. panicking immediately and reliably on the occurrence of a successful exploit? Yes, this is the definition of a DOS attack, but desktop users don't worry about DOS attacks; they worry about data loss and data theft. Modern filesystems are pretty resistant to data loss in desktop setups. And for getting back to work quickly, well, AROS boots in a few seconds on modern hardware. Does this make any sense?