Big Ideas.
For the past 5 years, Apple has been on auto-pilot, on a trajectory set by Steve Jobs before he passed away. The thing about big ideas and innovation is they change company trajectories quite drastically. Apple has, for the most part, been iterating on old ideas, and been doing fairly well (financially anyway).
As soon as I saw the watch, I knew there was a problem(never owned one).
In my opinion, Apple's current mindset would see them abandon the Mac, rather than give users reasons to upgrade. They probably see more value in a 1-2 yr lifecycle product than nurturing a platform like the Mac. They also seem to be taken with the latest buzzwords and fads.... wearibles, VR/AR, cars, etc....and i put the emphasis on the word *fads*.