"then I think you will find your way out if the need arises."
Yea I know that is the usual thinking. However, you are probably not going to leave the aircraft because the engine quits. So the plane has suffered some sort of catastrophic failure. Maybe structural, maybe limitation of the control movements. If it is limitation of the control movements the aircraft might well be recovered to level flight and a bale out performed. In the other scenarios it seems to me the aircraft may already be at low level in an "unusual" attitude. Practically how likely are you going to be able to exit the aircraft - I just wonder? Has there been any cases of a pilot baling out of a light aircraft after aerobatic failure?
I agree with everything you say about disused air fields. I am just not convinced they are a sufficient requirment to attract some pilots to carry out all their training in one area, causing a local nuisance.