A few years ago I would have agreed with you, but I've been very impressed with the subtly moving backgrounds on some Android phones (Samsung?), which attract little enough attention that it took me a few weeks to register it at all. I'm no longer convinced that movement is inherently distracting.

I agree that I can't see a really compelling functional usecase here, but aesthetics is a worthy goal in its own right. I'm cautious, and animation will almost certainly make icons worse before it makes them better, but I can see potential improvement, and I'll always err on the side of expanding toolsets.