I think you are kind of skewing the argument here in that for an Australian to work overseas outside of Cathay or the Middle East you need Jet command time.
Since that in Australia takes roughly around 15ish years from your first flight to get that experience most people don't want the hassle of moving again. GA and or the Air Force is enough hassle for anyone without having to go through it all again in a country where English isn't spoken. No foreign airline is going to take 21 year old 200 hour Australian pilots and park them in the RHS of a 777. The other problem is Europe who don't have all the BS GA to wade through so jet experience is much faster and easier to come by.