There's plenty of lazy folk both sides. Maybe the Aussies are more open about it than some.
My Aussie OH works hard to the extent that I wish he'd take time off for some R&R sometimes. But that's his personal work ethic, and who he is.
There's no doubt that Sydneysiders are expected to put in extremely long hours. They have to to afford property there! Also it's a very competitve world class work arena there.
My personal thoughts are that you can't always generalise, but on the whole, Aussies are not on that hamster wheel of work as much as the average UK worker. Yes you could call it lazy. You could also say relaxed, laid back, less stressed. Healthier even.
Maybe it comes from the climate. The Caribbean nations tend to have a similar attitude. It can be infuriating to deal with, but I get the feeling they enjoy life more than us workaholics. Anyway, if we choose to live there, it's up to us to ajust, shut up, or get out. (ok, we can also moan quietly to ourselves when pushed)!
I intend to join in and enjoy it, after half a lifetime of stress and burn-out.