Walk the talk?

Met up with head of an government funded agency the other day to talk about the need to create a vision of what living in low carbon communities would look like - including the certainty that we'll need to fly less if were to achieve a secure future. His response was along the lines of "there's no way that I'm going to stop flying to see my family". Why is that those in positions of paid public leadership on issues that affect the safety of life on earth aren't selected for their ability to walk the talk?