I suppose part of that is because WA is one of the few places in the country where you can drive for six hours and get absolutely nowhere. They're already isolated as fuck.Heh.
That's not exactly true, though. There were (and still are in places) heavy travel restrictions between States and even at times travel restrictions between regional and metropolitan areas. Western Australia is still pretty much closed off from the rest of Australia but polls have shown that most Sandgropers are fine with that as they're under almost no other public health restrictions (and they tend to be psychologically closed off from the rest of Australia in general).