Rather missed the point there Maxbear. Didn't write that I wasn't aware of the "rules", just that I don't see the point of being that anal about how they run their airfield.
You might have noted that landing at Oban was optional in my case and for a little effort on their part they made a few quid towards the coffers and another few quid was spent in the local economy for lunch.
i.e. I am a customer and they are providing a service which I pay a fair price for and there must be some dynamic between service, price and recurring income.
Surprisingly enough quite a few others did get the point, so it must be you that has difficulty in understanding