Two things. One, why should I have to do this painful procedure? Apple designed the product to restore from backup. If I have to do this it means there is a bug and if there is a bug Apple should acknowledge it and fix it.

Secondly, from the huge threads on the Apple discussion board it seems there is a serious issue with many thousands of phones. Here is just one of the threads https://discussions.apple.com/thread/4329696?tstart=0

For some people a DFU is helping, but the iPhone 5 still drains way faster than the 4. Some people are just getting new phones at the Apple store which now magically work fine. Some people theorize there is a serious battery problem, others think it was a faulty factory flash. Either way BatteryGate is the new AntennaGate. Apple took months to acknowledge that, and they are refusing to acknowledge the battery problem now. One Apple rep even said "of course the iPhone 5 drains the battery faster. It has a larger screen".