Thanks to EASA hooks are now lifed. I think, at 2000 operations. I understand the hook is deemed to be operated if the release is pulled - so that includes checking operation before flight. Similarly, the aerotow hook is operated on each launch even if it's a winch launch so it's using up its 'life'! Crazy!
Clubs have to get their income from somewhere, and making a time based charge for using the asset seems reasonable to me. If there was no charge and someone could take a launch and sit in the glider all day, the club wouldn't make much contribution towards its costs. There would also be a lot of unhappy people on the ground waiting for flights in what is, inevitably, a limited resource. Having said which, some clubs I've flown at limit soaring charges to, say, 2 hours, for approved cross country and 5 hour duration attempts.