Buckshot
You're not quite right in what you say. QF still fly to quite a few ports that you mention... they just don't use QF aircraft.
As East West Loco points out there are quite a few QF code share flights out there... only Australian travel agents can't afford to sell the QF side of the codeshare due to the low commission.
Just imagine if all the flights from Australia were code share. We'd end up with a brand name only, with no substance behind it... trouble is that it would make money and create a lot of unemployment in Australia. We don't need that.