The job of Director these days is a very heavy one, more so the chairman. The Board is there to protect the assets of the shareholders, to ensure that the company is operated within the law and to ensure that the principles of good corporate governance are followed - that means the process by which decisions are made and most importantly, to ensure the risks are understood and managed.
The penalties for failing in these duties are severe and for an entity like Qantas in its current situation, I would imagine that Directors lose quite a bit of sleep every night.
The Board only really should influence business strategy at one remove in my opinion. If they don't like unions then they hire a like minded CEO. If Qantas is going into China, then the CEO (Dixon) would have had to convince the Board that this was a good idea, not vice versa.
These days, a Board members job is not for the faint hearted. They are dealing with issues that would scare the pants of the average employee. I have lost count of the number of "would be if they could be" types who thought my CEO gig and Directorships are a doddle once you know the secret handshake. They aren't and I while I criticize Qantas strategy, I've never said that Alans and the Boards jobs were easy.