That's what the various bodies would like you to think, as making things black and white makes their life easier, and keeps them friendly with the various trade organisations.
I gather it is now legal for a professional electrical engineer to do their own wiring in Queensland, just they can't do it for third parties. By my reading, it is also generally okay for anyone to work on an "extra low voltage circuit", meaning less than 50Vac or 120Vdc. At the same time, the various energy authorities will claim it is illegal to install your own solar panels, and their publicity material says you can't do any wiring. The actual law seems to say you can DIY, just that you would need an electrician to connect the 240Vac side of an inverter to the main.
Workcover applies an additional layer of regulation in industrial situations. There also seems to be a requirement for an electrician to do solar work to qualify for various green rebates, despite the electricity regulations saying its okay.