I'm Australian too and this hasn't really been my experience, though. I have heard of this kind of thing happening, but perhaps I'm watching different tv channels or circulating in different communities to you or perhaps I'm just naive but your comment sounds kinda exaggerated.

Mind you, I watch the Chaser and they do make fun of Austalian idiots being idiotic in the way you described, so, idk, we're not all like that I guess?