I was picked up by a relative at Cranfield, had a nice day flying, and when we returned were a little surprised to be told by ATC the airfield would be closed by the time we got there. So we returned to his home base at Southend, and drove back
I went back to the tower the next day to pay the landing fees for the morning and was chatting to the guys about the opening times. They explained the airport used to be 'fully open' from 9 to 5 with atc and fire/fuel/coffee etc, and 'a bit open' out of hours, with just some empty concrete to land and park on, mainly used by the planes based there.
The owners had changed that to either "very open" or "very closed". the word insurance was mentioned.
I guess other airfields are in the same situation. If you let someone use your runway and they mess it up, and you weren't there to guide them, and mop up, it's your problem, not the pilots.