Governor-General's powers

I always thought Governor-Generals of the Commonwealth Realm has only a ceremonial role just like the Queen and never participate actively in any political matters. I've just learned of an exception. In 1975 Australia suffered a constitutional crisis because the Senate withheld supply to the government. To resolve this crisis the Australian Governor-General, Sir John Kerr, dismissed the Prime Minister, Gough Whitlam, and called a dissolution election for both houses of the Parliament. Yet, it was subject to controversy because of the convention that the Governor-General's reserve powers be exercised with Ministerial advice. John Kerr even became a drinker due to pressure from the public. Although I agree that Governor-General's reserve powers should be used with extreme caution, I do not totally disagree with Kerr's action. Whitlam's government and the Opposition were both playing politics threatening each other. The Budget was blocked for almost a month!! Something had to be done to resolve such a crisis, right?