How much time have you got? I guess the biggest factor is that referendums are hard to pass in Australia, especially when the campaign becomes partisan. And this one was VERY partisan. But also Australia has a particular type of racist ignorance when it comes to our First Nations Peoples and our colonial history in general. We’re now currently the only settler colonial nation that has not recognised its First Nations Peoples in their constitution. Settler colonialism is not a competition, but if it was Australia kind of wins the gold. I say that as a white Australian.
Australia rejects proposal to recognise Aboriginal people in constitution (www.theguardian.com)