I moved to Aus about five years ago after living in the US for 7 years and growing up (and getting my PPL) in the UK. I converted my PPL when I arrived and I've gone on to get my CPL recently.
I have made a couple of my own observations about the demise of GA here:
There appears to be a missing generation of PPLs in Australia - there are plenty of old fellas and plenty of debt-laden young boys and girls who want to press buttons in a shiny jet, but where are the younger and middle aged folk who want to fly for fun? The older guys and girls are gradually retiring and the young dreamers want out of GA ASAP.
I don't think flying is any more expensive relative to earning compared to 20,30 or 40 years ago, so there must be something else responsible. I'm sure having more and more pursuits to spend your money on is a factor, but my theory is that there has been less and less general interest in aviation in Australia and that this is fundamentally linked to the lack of public exposure to aviation. The only time the public see aviation is (i) RPT (in foul mood after being stung for parking etc) or (ii) prangs - i.e. never in a positive or exciting/inspirational light. GA firms are universally terrible at any sort of marketing (sticking a sign on the roadway outside your school is not sufficient in this day and age!), so I suspect the best way of swaying people toward aviation has to be through events like airshows. In the UK during the summer you have several big events every weekend and I believe these have been and continue to be instrumental in getting the general public interested and engaged with aviation. The US has airshows, fly-pasts at sporting events and of course the young eagle program. Maybe we have to plumb the depths of something like those awful reality TV shows
but we need something that makes people sit up, see flying and think "that looks like fun and I can do it".
Getting people through the door is only the first step; consistent with Oakape's experience my initial impression with several schools around MB was terrible - At best I was treated as an inconvenience and the school cat was most frequently the friendliest and most helpful member of staff. Most surprisingly this bizarre attitude to strangers (i.e. potential students) hasn't really changed much since the disappearance of the lucrative overseas zero-to-hero cadets after the GFC. This is a complete contrast to places I've been to in the UK and US, where the staff of the flying schools I trained at would be tearing your arm off to show you their aeroplanes, fill you with coffee and talk about flying. Why do schools and clubs insist on shooting themselves in the foot after doing the hard part of getting people through the door? I trained at four flying schools at MB until I settled on one that I actually enjoy being at.
I don't think all is quite lost yet, but the status quo will not only lead to a slow agonizing death!
G