And, in the time it took them to implement this (or, probably a HECK OF A LOT LESS), they could have actually implemented some useful features their user-base has been screaming at them for (in some cases for like 7 years!).
For example, the photo library doesn't let you select a group of images and 'download' them locally, oh I don't know, so you can actually USE them!
Or, one of my favorites, being their claim to fame was a video library... they you similarly can't just easily 'download' those videos/moves to your local device to take with you. You have to 'sync' them, which means they often get re-encoded/transcoded, which means if you pick a half-dozen movies for that upcoming trip, you'd better hope you did that a week in advance!