It's funny. We're a nation of few people, spread across a very large piece of land. You would think that coverage would be a critical issue for telecoms, but it's not.
As a fellow Aussie, lack of coverage is why I moved (back) to Telstra; outside of the major cities, only Telstra has reasonable coverage. Whenever I visit my parents in Gympie (~2 hours north of Brisbane, ~20,000 people), my previous carrier (Vodafone) couldn't connect me in the town's main street. Optus could only do so at a certain corner. With Telstra, I receive ~2mbps in the middle of my parents' farm. The difference in coverage between Telstra and its competitors is extreme.
Yet, Optus and Vodafone are two major carriers with millions of customers. Optus and Vodafone are not much cheaper than Telstra. But this small price difference (I'd actually be paying more for my equivalent plan with Vodafone..) is apparently (according to those millions of Optus and Vodafone customers) worth sacrificing a huge amount of coverage for.
tl;dr - Aussies don't seem to care that much about coverage, just price.
Because most people never leave the cities (or do so very rarely). They do, however, have to pay the extra per month. Telstra's extra coverage just isn't worth $120 a year (to some/most).
As a fellow Aussie, lack of coverage is why I moved (back) to Telstra; outside of the major cities, only Telstra has reasonable coverage. Whenever I visit my parents in Gympie (~2 hours north of Brisbane, ~20,000 people), my previous carrier (Vodafone) couldn't connect me in the town's main street. Optus could only do so at a certain corner. With Telstra, I receive ~2mbps in the middle of my parents' farm. The difference in coverage between Telstra and its competitors is extreme.
Yet, Optus and Vodafone are two major carriers with millions of customers. Optus and Vodafone are not much cheaper than Telstra. But this small price difference (I'd actually be paying more for my equivalent plan with Vodafone..) is apparently (according to those millions of Optus and Vodafone customers) worth sacrificing a huge amount of coverage for.
tl;dr - Aussies don't seem to care that much about coverage, just price.