Sync has always meant merging semantic changes in state between two or more devices. If I buy an app on my desktop and take 4 photos on my phone, when I sync the two devices, I expect the new app on my phone and 4 new photos in my iPhoto.
As version control has taught us, merging changesets can lead to a menagerie of pathological cases and there's no universally correct automatic merging tool. iTunes in the grandfather's case, chose to merge incorrectly and lose data.
Sync has always meant merging semantic changes in state between two or more devices. If I buy an app on my desktop and take 4 photos on my phone, when I sync the two devices, I expect the new app on my phone and 4 new photos in my iPhoto.
As version control has taught us, merging changesets can lead to a menagerie of pathological cases and there's no universally correct automatic merging tool. iTunes in the grandfather's case, chose to merge incorrectly and lose data.