Yet most of the rest of the world - particularly the bits of it you'd actually want to live in - has higher taxes than Australia...
People are leaving because the country has been run into the ground by greed, jobs are scarce, and our system panders primarily to rent-seeking (and especially the parasitical FIRE sector - negative gearing and Costello's catastrophic CGT changes mentioned above, petrol on the fire for the property bubble - being prime examples) rather than productive industry.
The success of post-WW2 USA puts paid to any argument "high taxes" inherently impede growth, innovation and entrepreneurialism.
Off topic, but what do you mean by this drsmithy?