(Mac) OS X has been around since, say, 2000 (Public beta)?
So, after 13 years we (OS X) get features from an OS which is only a few years old....
Since 10.6, OS X has been about "iOS-ification" of Mac OS. And rightfully so.
The Desktop OS of Apple has been the same for many years. Sure, new hardware is supported, new apps, new cloud-integrations, etc... but the way the OS works for the end user hasn't really changed since the first OS X. TBO, not really changed since the Lisa OS...
Desktop, the Finder, and Applications. All "controlled" by the keyboard and mouse.
iPhone OS (& iOS) is the first OS to make the "way it works" change. This "portable OS" alongside the use of touch screens has changed the way we work and play with the devices.
Apple is trying to integrate the new style of devices with old style computing. What can Apple do more to the ancient desktop OS than integrating more of the modern iOS features?
Innovation is long gone with the desktop OS.
Even Microsoft has got that one. That's why they have come to the conclusion that Tablet OS and Desktop OS might as well be one, right now.
This "almost post-PC era" in which we live in right now might be a significant time in the history books of the future. The junction of classic PC's and modern i-Devices.