Yes, it&#x27;s completely rubbish, I agree. I&#x27;m pretty sure the people who are working on Time Machine are aware of this problem and I&#x27;m pretty sure it stems from the unreliability of mounting disk images over a network. Quite possibly due to hardware issues (e.g. flakey AirPort&#x2F;Time Capsules) or problems with HFS+ filesystem. At a guess, I&#x27;d say they had to do their best to work around these issues. There is no excuse though, especially when it comes to backup.