CEOs can't be experts at everything and often don't have the time necessary to research everything they need to research. So as such it's quite reasonable to get people to help them out, especially when you are a new CEO and have to get up to speed really quickly. Getting people from outside the company rather than inside the company minimizes the chance of the information the CEO gets being biased by deep rooted corporate culture or by sycophants or back-stabbers looking out for their own best interest.