A majority, I was surprised to discover, were not Afghan but Iranian. Most were from cities and the lower middle class. They were builders, drivers, shopkeepers, barbers. One man claimed to be a mullah; another, an accomplished engineer. Their reasons for leaving varied. They all complained about the government and its chokehold on their freedoms. A few said they had been targeted for political persecution. They bemoaned the economy. International sanctions — imposed on Iran for refusing to abandon its nuclear program in 2006 and later tightened — had crippled their ability to support their families. They were fathers who despaired of their children’s futures, or they wanted children but refused to have them in Iran. The most common word they used to describe their lives back home was na-aomid — hopeless.
The answer is just a small number of countries in the western or southern parts of Latin America and in the Pacific. Even Sao Paulo in southern Brazil is closer to Tehran than Sydney is.
Grozny, Chechnya: 622
Tashkent, Uzbekistan: 1,061
Nuuk, Greenland: 4,407
Dakar, Senegal: 4,444
Cape Town, 5,240
Anchorage, Alaska: 5,664
Mexico City: 8,184
Stanley, Falkland Islands: 8,869
Easter Island: 11,172
Whether Pitcairn Island is nearer or farther than Easter Island is hard to tell because it doesn't have an airport.
Moreover, unlike with Afghanistan and Sri Lanka, no agreement exists between Iran and Australia allowing for the forcible repatriation of asylum seekers whose applications are unsuccessful.
But, the main reasons are that Australia is lightly populated, and set up by and still (mostly) run by Northern Europeans.