I've been there. It is an extremely remote place, where the locals all know each other and it is very beautiful but with some of the worlds most dangerous sharks paying regular visits to the beach. And when you look across that beach, you are literally gazing off into the horizon of the end of the Earth. There's literally nothing between Esperance and Antarctica.

Its no wonder the place breeds the silent types.

i think it means the effects of living in a small community far from the rest of civilization. where i am from people living away from cities, especially in the mountains also have a reputation of not talking much. i think in the US too.