It's a privilege becoming Australian by 4 years only. Where I come from migrants have to wait 8 (!) years before they are eligible.
In my point of view Australia is still very generous offering citizenship, even they've changed the laws and rules from 2 years in 2007 to 4 years in 2010 (introducing the citizenship test, too).
Hopefully, they don't change the rules again after the election. When I think of New Zealand, where migrants have to wait 5 years before they can apply...
And Australia recently adopted New Zealand's skillselect migration scheme, which made it more complicated to get a permanent visa at all.