Why would a CEO be interested in adopting a Lean approach?

I was examining an MSc student last year, when the second examiner asked Why would a CEO be interested in adopting a Lean approach? The student found it difficult to answer.
Choose an organization as a context in which to develop an argument for the CEO that explains Leans role in creating value for the organization. Although customer value is often the focus of Lean, your answer should focus on value for the organization.