Well, when a basic C172 that sold for less than $150K in inflation-adjusted dollars now sells for a half-million dollars, I would imagine general interest would be abysmal.
Pretty much nailed it:
I would imagine general interest would be abysmal.
The problem with GA is that there is very little general interest. Oh sure, there's been a bit of an uptick recently, but overall the apogee was 1978 and GA has been declining albeit with a sinusoidal downslope ever since. In the late 70s the WWII generation, which was aviation crazy, reached their peak earning years, which coupled with empty nests, allowed them to buy their dream planes, be it a 172 or a Bonanza or a 210, in droves. There were something around 17,000 bug smashers delivered in 1977 or 1978, the peak year. The bounding years around the peak weren't bad either, but then the bottom fell out. Essentially everyone who wanted a plane now had one.
In the ensuing almost 50 years, of which I've flown almost 40 of them, so many small private airports not far from a town or city one might want to visit closed when their founders died and the inheritors turned them into housing. This greatly reduced the practicality of going from point A to point B, particularly on the coasts. The beautiful county fields spaced every 20-40 nm between the Appalachians and the Rockies did survive, but the population and hence economic density is lower there, making it harder to sustain sales. So now one must often fly to a fairly big and busy airport to do business or visit friends and families. All workable, but the economics are just not accessible to very large population.
So now we have about 150,000 piston aircraft in the US and somehow there's an idea that if someone just built a $100k (same as a big pickup) four seater that went 180 knots for 600 miles GA would take off. Not in my opinion - in the end flying is not trivially easy as there's a commitment and a depth of learning required that surpasses most other hobbies people like to do, perhaps because the penalty for messing up can be the ultimate one. As a contrast, motorcycles, another somewhat niche product not terribly loved by many, often for the same reasons as light planes, sell about 500,000 examples per year in the US! That's all brands all styles integrated. Ford sells more copies of one truck, the F150, every year. We just don't get any economy of scale in aviation.
So enjoy the aircraft we have today and the miracle of flight. Maybe the machine is not as fast as one would like, and can't handle as much weather as one wished, and can't go as far, but it can FLY. And that's a miracle that mankind has dreamed of since first seeing a bird. Maybe your machine just flies, maybe your machine "goes places" but all the piston powered aircraft are pretty much in the same bucket - hand built machines that support a very small and niche engineering base.
Still rooting for the next guy building the 220 kt 200 hp miracle for $200k. Hope springs eternal.