>I'm not even sure domain knowledge is important for a CEO of a company that size: once you become a $50 billion plus company, you don't have time to get involved with the details of the business.
Steve Jobs and CEOs in-between kind of make a counter-example.
Read the biographies of Steve and Steve; Jobs was not an expert, but was familiar with technology of that era. His father taught him electronics, and Jobs was working at Atari as an technician.
Steve Jobs and CEOs in-between kind of make a counter-example.