I think Ive has burn out issue at the time and has clearly thought about departing Apple. ( A book chronicling 20 years of Apple's design in 2015 ) He wanted to design the perfect and final thing and so MBP was rushed. Steve Jobs would have worked him and likely said hey this is good but we must do it incrementally so our user can adopt to changed. How about the Keyboard keys goes to 1.2mm instead of straight to 0.7mm key travel.

It took us 20 years for humans to adopt from the good old 2.5mm keyboard to 1.5mm. And you want to cut in half again in one go?

I think it is best summarised as Steve Job's quote in the movie;

"Musicians play their instruments. I play the orchestra."