An interesting discussion. The US news report was silly, but there is much more to the subject. Australia's (and most Commonwealth countries) have political systems with strong roots in the work of the British philosopher Hobbes. His view was that, left to themselves, people would default to violence and have lives that were brutal and short. He used this to justify the need for government. Basically his view was, "you can't trust people, so you need a government to keep them in order". A later view was put by Locke, (also British), who was more optimistic about people. He thought that most would live peacefully, but government was needed to control those who didn't. He was more sceptical about government though. He thought there was just as big a risk of them becoming tyrannical and that people always needed to have a means, including revolution if needed, to topple such a regime.
British commonwealth political systems are dominated by Hobbes' views, but the US Declaration of Independence and Constitution is very much based on Locke (almost word for word in places). The ability of a people to topple a tyranny is what drove, and still drives, the US second amendment. To trust in government to them appears naive and 'childish'. Australians will find that puzzling, but the history of the two countries is quite different. The USA had an armed revolution. When they tell the Paul Revere story ("The british are coming") it was about the British coming to take over their armouries so they couldn't fight. They had a Civil War (with a population then of about 35 million, there were over 600,000 deaths - that's a much bigger event than Gallipoli was to us in comparative terms). They have a wilderness full of large and dangerous predators. They had Indian Wars that make our wars with Aboriginal Australians look small. They have a tradition of emphasising self-government, setting up their own systems and often electing their own law enforcement chiefs, whereas we have a tradition of meekly importing English colonial practice in almost everything. That makes for a society in the USA that values/trusts self-protection way more than ours.
Some parts of Australian state gun laws are good. Few civilian shooters in Australia would argue with things like safe storage, safe transport and licensing, but would suggest some of the registration practices and level of enforcement regimes have no effect and are very costly. Countries like Canada and NZ don't have the latter, yet do almost as well as Australia in preventing gun deaths. Countries like Germany (three times the gun ownership rate of Oz) have tight gun control regimes, but they are heavily risk-based, whereas ours are part risk and part politically based, and they engage positively with the legal civilian shooting community rather than treating them with suspicion and contempt. The Swiss have a very high rate of gun possession, but low gun deaths (I notice a recent newspaper article disputed this, but only by conveniently moving the decimal point on the death rates to look more like the USA).
If you look at the statistics for gun deaths in Australia over many years they have been strongly in decline. The rate of decline has been about the same before Port Arthur as after (anyone claiming otherwise can only do so by comparing the worst single year before, with the best single year afterwards - the general trend is the same). That's not an argument against gun control, but it is an argument for understanding what is causing the decline and working with it, instead of claiming it's a result of gun laws that were only there part of the time. 78% of Australian gun deaths are suicides. While gun suicides have declined, overall suicides have not. The absence of access to a firearm is hardly likely to deter an unfortunate person considering taking their own life by any suitable means. Sadly we get excited about gun control far more than about the much bigger problem of suicide in general.
The firearm ownership rate in Australia is about one tenth that of the USA. Lots of firearms in the USA are of the type that can be used in mass shootings (notably semi-automatic, centrefire longarms). These were used at Port Arthur, but are comparatively rare in Australia (only 3% of the firearms in the Australian gun buy back were of that type). There has never been an American type gun culture in Australia and there never will (regardless of regulation or not) because our histories are so different. The Eureka Stockade was an armed rebellion, but its leaders achieved more through parliamentary means in the years that followed. We tend to have a history of trust in government (though not necessarily politicians) greater than in the USA. The prohibition of firearms in the USA would be likely to have a similar effect as the prohibition of alcohol there in the 20s, if not much worse.
Gun control is politicised to the level that makes rational discussion difficult. Any attempt at making the existing Australian laws more rational, effective and cost-efficient is often met with a hysterical response. At its core there is a real risk that needs to be controlled, just like there are real core risks in things like terrorism and climate instability. But in all of them, politicians and lobbies use exaggeration and over-simplifications to appeal to our fears. ("Vote for me and I will protect you against these scary things.") And there is also the biggest difference between the USA and Oz. Here it's only the anti-gun lobby that use such tactics. In the USA it's both sides, with the NRA using the second amendment, among other things, to exploit a fear of tyranny in the tradition of Locke.
The question will be asked as to whether I am a shooter. Yes, I have had a shooting licence for a few years, which is why I know quite a lot about the subject. But please feel free to research and verify anything I've said. In closing, I have also been a pilot for many times longer. As you would all be well aware, aircraft have been used (including in Australia) as weapons for mass killing. The aviation industry certainly has more security since 9/11, but strangely I am never thought of as 'risky' because I fly, yet there will be some who think that of me because I do competitive sports shooting. I've also been a firefighter, so I know that the arson death rate has doubled in Australia in the last few decades, including three mass killings (Childers, Quakers Hill and part of the 2009 Vic bushfires), yet that gets little press.