1. How can the user know how much battery power is required to complete the update? If they don't know, they can't utilize the option effectively.
2. If the system knows, why not let the system manage the sleep behavior? iOS won't let you start an update if there isn't enough power to complete it.
3. Why would there be sudden loss of power leading to data loss? Surely the system can determine when the battery is at a low level, and a) Warn the user a few minutes before they need to stop working, and b) Provide the applications with an orderly shutdown sequence. Guess what? iOS does both of these.
This is certainly a design fault. Your scenario doesn't change that. It merely offers that this feature is needed in order to work around other design faults.
1. How can the user know how much battery power is required to complete the update? If they don't know, they can't utilize the option effectively.
2. If the system knows, why not let the system manage the sleep behavior? iOS won't let you start an update if there isn't enough power to complete it.
3. Why would there be sudden loss of power leading to data loss? Surely the system can determine when the battery is at a low level, and a) Warn the user a few minutes before they need to stop working, and b) Provide the applications with an orderly shutdown sequence. Guess what? iOS does both of these.
This is certainly a design fault. Your scenario doesn't change that. It merely offers that this feature is needed in order to work around other design faults.