Forget what he does for a second, and think about this: he is a 67 year old man, not considering immediate retirement, but announcing to Australia that he's planning to extend his career even further. Why wouldn't he? He's fit, he's capable, he's experienced.
As our population ages and our workforce numbers decline, we need these Boomers. We need them to work, pay tax and live independent lives. So if you're employing people right now, go back to that pile of over 50s you dismissed and take another look, you're wasting a valuable Australian resource.
Oh, and employees are already talking about you, yes you, the employer who doesn't want older workers. When the workforce dries up and you're begging for workers, don't be surprised if this comes back to bite you.
The workforce is changing, workers are picking and choosing jobs (and employers) even now. Consider yourselves on notice.