Steve Burkes did not become CEO overnight. Like other businessmen, he started climbing the ranks by doing well in his different jobs. He actually worked for Disney before he transferred to Comcast Cable as president. It was in the year 2004 when he was declared to be the new CEO of Comcast Cable.
In the year 2010, Comcast Cable wanted to acquire NBCUniversal fully, and when the merger finally happened, Burkes was declared to be the CEO of NBCUniversal. It took him a lot of years in order to get the type of position that he wanted. Now that he has already achieved it, he would like to retire and give up his position.