I thought the 12 noon rule was to enable any people currently on your pitch to vacant in enough time etc. Also as a lot of the sites are off narrow country lanes or dont have much room for arriving vans, there is the potential of those trying to off the site, blockd by those trying to get in.
Its not just the CC though, the C&CC also operate like this and i must say, having seen the queue, (15 to 20 vans) along the narrow single track lane trying to get into the windermere site, i can understand why. I foolishly tried to get out, (driving solo) at 4pm on a friday and was in the nearside hedge for 1/4 mile until i got passed the queue. If that was at say 10am, no van could get out, menaing no vans could get in and a big problem is created.
All makes sense to me.
Eric's last point, i suspect has been hugely debated but i confess its the single reason i wont join the club. Its obvious that a large number of members just block book on whim with only a slight intention to go and to keep their options open. For a young family like myself, with 1 or 2 decent week breaks in the summer, we may as well write off any caravan club site if we use the online availablity checker.