Thing is with the Aus one is that because there are so few TV channels and aus produced programmes (think TV in this country 20/30 years ago) that something like this is a big deal and it is shown 6 nights a week.
Masterchef was the same when they brought it to Oz, every night it was on not like here a couple at most.
There are not so obsessed with watching different types of programming like brits and americans
So they like to watch it play out and watch the stories unfold. Brit and usa tv want fast quick fit tv and watch something like this once a week.
Here endeth my lecture