The scheme originated as a result of the CAA's
Review of General Aviation Fatal Accidents 1985-94
(c) There were a number of fatal accidents where a timely diversion or
precautionary landing could have avoided the accident. In the UK (and probably elsewhere) there is a ‘culture’ of pressing on and hoping for the best rather than accepting the inconvenience and cost of a diversion. This ‘culture’ needs to be changed, firstly by educating pilots and secondly by persuading aerodrome owners that there should be no charge for emergency landings or diversions. (There are some aerodromes that do not make a harge for an emergency landing.)
It is recommended that all aerodrome owners be persuaded to adopt a policy that there should be no charges for emergency landings or diversions by General Aviation aircraft.
The cause was taken up by Charles Strasser of AOPA. Details and a list of participating aerodromes can be found
here.
A good example of AOPA working for the good of all pilots, whether members or not. (If the cap fits, feel guilty and join up
)
Personally I agree with 2D's point of view. If you are mad enough to let the possible costs of an unscheduled landing affect your decision then you fail to demonstrate the competence to be in command of the aircraft in the first place.
PS
On the one occaison when I have had to make an emergency diversion Compton Abbas flatly refused to accept the money I was offering.