As long as the site is paid for there is little anyone can do about it. Simply reserve ahead or get there earlier to avoid this dilemma. Same thing goes for little trailers taking up large sites, plan ahead or deal with the consequences of not getting a site that can manage your rig. We arrive to many of our state and federal parks and see many sites vacant but reserved and don't fret about it since we knew we didn't take the appropriate actions required in advance. We normally don't reserve ahead of time ourselves unless we need a guaranteed site for a busy weekend.