I mean, a meteor could hit the DC. But I guess that would count as a decommissioning event, wouldn’t it? So you’re still right, with a proviso—there’s never any reason to turn the machine off with the expectation of ever turning it back on.
If, for some reason, an event decommissioned all three machines, having our computers back online would be a lesser problem - we would probably be better off learning to hunt and make fire.
Your decommissioning event had me in stitches. I might use that phrase in the future :D