I'll try to elaborate: yes, there are of course certain things that you cannot avoid. That's why I meant you should not "rely"/"depend on the cloud without any alternative backup" on the cloud being available. Redundancy, if your service is crucial!
If you're a small company, and cannot go to your building for a day, well then I hope you're not that important so no big damage (financial or otherwise) is caused. Just enjoy your free day ;-) But if there's a bomb threat in, for example, a hospital, I surely hope they have some kind of backup plan!
Cloud as an alternative mechanism, or maybe even the primary resource for your site -- great, why not! But please don't just throw everything into "the cloud" trusting on the belief that the cloud's operator is impossible to fail.
You raise perfectly valid and interesting points. It's just a shame they're not the parent comment because then they would have invoked some thoughtful discussion.
How I was supposed to get ' "relying", as in "depending on the cloud without any alternative backup" ' from what your originally wrote, I don't know.