I have made two weather diversions. Both planned flights were into Bourn.
The first was a diversion into Cambridge due to low cloud. I was not charged for the landing, the ILS approach or one night's parking. Excellent!!
The second was into Cranfield. I was picking up ice in a non-deiced aircraft and could not get below the freezing level or out of cloud above the MSA. There was no charge for landing or parking.
In both cases I would have happily paid. My decision to fly in both cases included the consideration that Cambridge/Cranfield were available to me for diversion if conditions were worse than I expected and were part of the 'safe-flight' review prior to departure.
Nevertheless, I support the concept that cost considerations should not become part of the decision process, which could lead to a pilot pressing on in bad circumstances. In both of the above cases it would have been bad news to continue the flight to Bourn.
I am giving a reason why an airfield's participation in the 'no fee for weather diversion' scheme would have made no difference to me, but I'm not naive enough to believe that everybody would share my view.
AA.