> It's crazy to develop very similar APIs for GUI apps in parallel, and what has become two different OSs with slightly different apps and feature sets, but a huge amount of overlap. The savings for Apple and developers of having a consistent set of new APIs and one set of apps to manage (for example their entire office suite) would be huge.
Right, and what the announcement seems to show is that UIKit could eventually grow to replace AppKit. Like you yourself say - "uikit is a better appkit written with the benefit of experience".
That still doesn't imply the two OS would necessarily be merged - there's still a ton of things that make sense for macOS that are not needed in iOS, and vice versa - just for one thing, they have vastly different energy budgets. There's also a ton of overlap and shared code already, for pieces that it does make sense to share.
So, I still think the answer is really targeted at people who fear that iOS (with all of its current limitations) will replace macOS, essentially, rather than being a misdirection as you seem to find it?