There is a rather more basic consideration here, which appears to have been overlooked.
Flying is not a cheap hobby. It's not like F1 racing but it does cost more than fishing.
Currently, most people who enter GA don't get very far. They barely have enough to do a PPL; most pack it in soon after. A number of reasons no doubt; money is one (but they must have known!!), lack of utility is another (most rentable planes are crap), crap social scene (most airfields are full of anoraks, and most prospective passengers won't fly in crap old planes).
Now stand next to the M25 (or any other road) and count the £50,000 cars. Due to all the tax changes, many of them won't be company cars. Even fewer of the copious quantities of £100,000 cars will be company cars. There is a lot of money about. Most of the drivers are executives or people at the top of their profession - not the stereotype stupid people with inheritances.
Here's a question for the instructors: how many people with a realistic flying budget (PPL and post-PPL) do you see, as a percentage of all punters that get past the first lesson?
So, why do so many apparently good pilot candidates avoid GA? May I suggest a few factors:
1. A desire to keep everything in the past
2. Outdated procedures (the circular slide rule is a really good example) when it's obvious to anyone with a brain that there are better ways
3. Anoraks everywhere (result of 1 2 4)
4. Lack of women (result of 3, mainly)
So, while one is debating the circular slide rule and how brilliant it is for sorting the men from the sheep, anybody with a brain (and a car whose wheels won't fall off anytime soon, probably with a GPS in the car) who gets anywhere near a trial lesson, will politely smile, turn around and walk out again.
It's a very quaint scene around airfields, old chaps, with the tea, the cakes, the WW1 biplanes with pilots (mostly in their 60s and 70s) in leather caps and leather jackets.
I am sure re-arranging chairs on the Titanic was a fun job, too.
It's time to move on, ditch all this old rubbish and drag GA kicking and screaming into the 20th century.
Will it happen? No way. My kids will almost certainly not be flying. Not because VFR GA will be outlawed, but because the shrinking GA population won't support the present GA airfield network. Once these start to close, things will move fast. The UK will become like Greece or Spain, with negligible GA activity.