It's fucking hard to walk into a cinema and kill 12 people with a hammer. It's the efficiency of the tool at doing its job.

As stated in that article:

These national gun laws have proven beneficial. Research published in 2010 in the American Journal of Law and Economics found that firearm homicides, in Australia, dropped 59 per cent between 1995 and 2006. There was no offsetting increase in non-firearm-related murders. Researchers at Harvard University in 2011 revealed that in the 18 years prior to the 1996 Australian laws, there were 13 gun massacres (four or more fatalities) in Australia, resulting in 102 deaths. There have been none in that category since the Port Arthur laws.

So why would I need a gun? Maybe the problem isn't the guns, maybe it's the people. Maybe the rest of the westernised world isn't as fixated on killing each other? Our crime rates are lower than the US, yet we have no guns to protect ourselves from criminals. Some of our criminals do. But it's rare because they're not easily available. The chances of me being attacked are very slim, and I'm not scared to leave my home at night. And yes, I've been mugged, in the UK (and if I had a gun I still wouldn't have pulled it as I was significantly outnumbered at the time).