I haven't run across any that charged for guests yet but I can understand why certain CG's do it though.
Especially if there are a lot of amenities in the CG AND CG is 'located near a big town' or attractions.
If the CG is near a populated town I can see the 'local people' getting/paying for one site and then inviting everyone they know come over just to use the amenities and party.
Personally as an RV'er I wouldn't want to be parked next to a scenario like that with 20 people running around on each CG site.
Just saying I understand why they do charge for guests to prevent this from happening and my guess is that is why they started charging extra to stop it. Not to punish the real RV'ers. But when you have a rule you have to stick with it. We are just collateral damage.:W