My personal opinion:
Is it really CASA and ASA and bureaucracy etc that are causing the demise of GA in Oz?
In the US where the regulators (apparently) have a much less intrusive role, airport owners charge less, fuel is cheaper, rules less burdensome etc, GA seems to be similarly declining.
How much of this is simply how the economy (and its effects on people) are changing the way people behave and view aviation?
GA thrives on new blood in the way of pilots, owners and operators. It cannot self sustain on an aging pool of private owners, small GA operators having trouble getting customers and the dwindling general flying school industry unless there are customers wanting to spend their money on aviation.
Operators need to make a buck, students need to be able to pay for lessons and not risk their mortgage, CPL trainees need to believe the cost outlay will allow at least the potential for them to get some sort of career path in aviation that might justify the cost.
Today I suspect it is not that flying costs have grown out of proportion to the average new blood punter's wages but that with the cost of housing in much of Australia, the average new blood punter is spending most of their income on paying off a mortgage. The median house price in Sydney is near a million dollars!
How can a 'median' family with a couple of kids in school service that kind of debt and have enough left over to get a PPL?
The previous new blood punters are too scared of what might happen if the interest rates go up or there is a recession to spend their left over money on getting a PPL or helping their kids go for a CPL or invest in an aviation business that is far from a sure bet given the current state of play of GA.
Flying costs need to appear to be within reach of the average punter. It used to be that way.
20 years ago I recall plenty of students from all walks of life from teachers, fitters and turners, builders, plumbers, salespeople etc who wanted to learn to fly (or were looking to have a shot at aviation as a new career and stumped up to work at a CPL).
They managed to find the costs at least within their reach (even if sometimes it was tight and they needed to spread their training out).
For all the talk of steady economic growth in Oz, that is not how many people I think feel personally about 'their personal economy' today.
I think that is why GA is dying not simply because of the regulators, bureaucrats or landing charges.
Not to say those costs/hurdles don't hurt things but I think the real issues run way deeper and are far more difficult to solve. Sadly
Look at how many schools and flying clubs there were back then compared to now.
Today? How many new students come in off the street? How many have an average job to fund it? I seriously wonder how kids (or older) can afford to get a PPL (or do a CPL) when most of your income is going into a mortgage or rent.