If you do a photo-app or a to-do list that can be the attitude.
If you have customers with enterprise needs paying enterprise prices, you need to keep your SLA. Think finance, e-commerce, etc.
If your Infra Provider has the same SLA than you do, you have problems and should do the math and think about backup infrastructure or what ever else is necessary to have a chance of upholding that SLA.
Edit: I just now see that you misunderstood me. With "backup infrastructure" I meant an infrastructure to do backups, not another new infrastructure to sit there and collect dust awaiting disaster. That's mostly not necessary.
If you have customers with enterprise needs paying enterprise prices, you need to keep your SLA. Think finance, e-commerce, etc.
If your Infra Provider has the same SLA than you do, you have problems and should do the math and think about backup infrastructure or what ever else is necessary to have a chance of upholding that SLA.
Edit: I just now see that you misunderstood me. With "backup infrastructure" I meant an infrastructure to do backups, not another new infrastructure to sit there and collect dust awaiting disaster. That's mostly not necessary.