During a media Q and A session at Cisco Live 2015, new CEO Chuck Robbins was asked why he was looking outside the company to recruit some of his new leadership team. His answer was interesting and might give some insight as to why internal promotions aren't as common as we'd like.
Robbins' answer was pretty simple.
Some really wise person said that 95% of the smartest people don't work for you. There's so many people out there. The right way to go about building leadership teams is a combination of people from the inside who really know what's going and then bringing in external expertise based on things happening in the marketplace.
Most of us think we can work at a higher level than out job level or pay grade but the reality is there are fewer jobs at leadership levels of a business than further down the food chain.
In my experience, the best leadership teams are the ones with a combination of internal and external people. They key is finding people who work well together and affirm the company's culture and values.
Disclosure: Anthony Caruana travelled to San Diego as a guest of Cisco.