>>1 It depends on the type of apocalypse we face. If we're hit with a powerful EMF, even old computers will be susceptible to damage. The only reason people use ancient PCs is because they're secure. They're only secure because they aren't connected to the internet, and can't be accessed wirelessly. If you got into the same room as the PC, you could do just as much damage to it.
Any other apocalypse we face will have alternatives to this technology.