Innovation and progress is driven by tangible measureable factors. For much of human history, warfare was the driver for technological progression (as evidenced by aviation itself).
More latterly capitalism and the never-ending search for profit has taken over - witness the internet, mobile technology and software. all have origins in military developments, but their drivers now are commercial exploitation.
And herein lies the problem for GA. It is a massively, hugely niche market (oxymoron intended). Without the massive increase in pilot training over the recent decades, GA might well have already stagnated and died, as commercial builders strive to find exploitable markets.
What is absolutely clear, is that GA is rapidly approaching its Rubicon. Legislation is simply not going to allow such a quantity of ancient hardware in our ever-crowded skies and over our ever-crowded towns and cities. Of course the legislators have a huge headache (of their own-making) to solve...how to evolve pilot training into a proper, structurally sound, and consistent process (like training a doctor or dentist for example) without totally ****ing up three quarters of the world's airlines, while so doing.
If that nut is ever cracked (and it really won't be easy) the future of GA in any format will be precarious.