And when you have 500,000 copies of something, most of which have been in use for some appreciable fraction of their effective lifetime, it doesn’t have to be “

And when you have 500,000 copies of something, most of which have been in use for some appreciable fraction of their effective lifetime, it doesn’t have to be “common” to occur to some fraction of them. The post you’re responding to never implied that it happens to _most_ of them, or even many of them, just that when you have a gigantic farm, it’s not unreasonable to see a small handful of hardware instances release up their magic smoke when they’re all coming back from being powered down. MTBF is a thing.