Their is a feeling that CEOs of these large companies are completely responsible for the direction a company takes. I have never served as a CEO, but I can't help but imagine that large share holders are also very dominant figures.

One of the attributes that Steve Jobs and Bill Gates appeared to share (I have never met either) was a massive amount of trust/faith to run their respective companies (eventually).

I imagine that this must translate to the board room where they were provided the freedom to pursue avenues that a newly promoted CEO would just not be allowed to do.

The author praises Steve Ballmer and Tim Cook for their ability to drive short term growth, but had they failed to do so they may have been replaced by someone more willing to focus on these returns. Eventually as disruption occurs the share holders start to prioritize facing these new challenges.