>Dozens of people in Australia die every year from their own 12 or 230V wiring
Do they? Your claim surprised me, so I did some digging:
Not from electrocution certainly, because as of a few years ago [1], there were only about 5-6 unintentional electrocutions in the home each year nationally, and that's all cause, not DIY electrical.
WRT fire, there are 4-5 deaths from preventable house fires annually caused by electrical faults (the leading causes being smoking and cooking) [2]. There is also a further ~1 death per year categorized as "misuse of electrical equipment". It's not clear into which category DIY electrical would fall, but it's not mentioned at all in the report.
If you hook a 240V appliance to 12V DC it will draw negligible current.
Perhaps you are trying to talk about people using a 12V to 240V inverter to run AC equipment in a car or off-grid, but not using large enough batteries. What-ever, the end result will be a flat battery or blown fuse, so little damage will be done. No worse than any other 12V wiring in a car.
Can you expand on this ? Do you mean their deaths, or some sort of economic suffering?