Penalty for Leaving a Site Early

Could someone from the Club explain if people leaving a site early and claiming a refund (and now get charged one nights site fees) was a sufficient problem to warrant this rule being put in place? I appreciate there has been a lot of discusion about cancelling bookings further ahead than 72 hours and can undertand that being put in place but the loss on a night fees if you decide to leave a site early defies logic.

David