I think we have stumbled upon the reason why there are no new Macs. Apple was wasting resources on the car.
Apple Inc. has drastically scaled back its automotive ambitions, leading to hundreds of job cuts and a new direction that, for now, no longer includes building its own car, according to people familiar with the project.
Zadesky handed the reins to his boss, Dan Riccio, adding to responsibilities that already included engineering annual iPhone, iPad, and Mac refreshes.
Source: http://www.bloomberg.com/news/articles/2016-10-17/how-apple-scaled-back-its-titanic-plan-to-take-on-detroit">How Apple Scaled Back Its Titanic Plan to Take on Detroit - Bloomberg