Such idiots for paying rent, even though building SkyScrapers isn't their core business.
This is an excellent metaphor.
Note that I've written "relying", as in "depending on the cloud without any alternative backup". Depending on the cloud means depending on something you cannot influence.
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.
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.
The back analogy works too. If you're an oil company, Goldman Sachs, AT&T or something similar, you have the bucks to pay someone for an empty emergency office complex for critical staff.
If you're anyone else, you're screwed when the elevators break/street floods/bridge falls down. That doesn't mean that buying a building or building a dam is a viable business continuity strategy.
A better analogy would be setting up a retail shop on a busy street where every now and then, the police completely close off the street, and when you ask them why they've done it, they tell you that it's none of your concern.
Yet, people still continue to open shops on this street, that is, until the customers start going somewhere else.