Great read from Steve Blank on visionary vs. executional CEOs and how Tim Cook is very much in the same place as Steve Ballmer was a few years back:
"When visionary founders depart (death, firing, etc.), the operating executives who reported to them believe it’s their turn to run the company (often with the blessing of the ex CEO). At Microsoft, Bill Gates anointed Steve Ballmer, and at Apple Steve Jobs made it clear that Tim Cook was to be his successor.
Once in charge, one of the first things these operations/execution CEOs do is to get rid of the chaos and turbulence in the organization. Execution CEOs value stability, process and repeatable execution. On one hand that’s great for predictability, but it often starts a creative death spiral – creative people start to leave, and other executors (without the innovation talent of the old leader) are put into more senior roles – hiring more process people, which in turn forces out the remaining creative talent. This culture shift ripples down from the top and what once felt like a company on a mission to change the world now feels like another job."