Yes, you absolutely _should_ design for that. That's why it's kind of hard to get mad at this shortcoming, because the answer is just that you should have been following best practices anyway.

In practice, though, I often found myself getting annoyed that I had that enforced on me. On AWS or most other providers I've used, if you have a workload that isn't particularly mission critical you can get away with just expecting the machine to always stay up. It'll probably only go down once a year or so. Obviously not the best way to design a system, but a handy tradeoff to be able to make in order to save a little cash or complexity.