That is just how fanime hotels roll. Many Congoers will go in groups and stuff as many people as possible into a single room to save cost, beds be damned. Of course, having 10 people in a room is a safety hazard should there be a fire or some other emergency, but as long as they are within safety regulations they allow for there to be more people then the beds can hold. The vast majority of congoers are aware of how this goes and decide if they want to shell out the cash for a less occupied room or (more likely given the limited number of rooms available) room up and save cash. It is not like they are swindling anyone though, they are quite clear with what the rooms offer, so I don't see any issue. I don't know why their reputation would be affected by allowing their customers to room how they please (within safety standards), and even if was affected, I am quite positive their reputation would already be ruined for allowing congoers in their facility (
see Rainfurrest).
As for a single King being occupied by 4 people, that is pushing it for sure, but most years we have 3 people in a king bed easily enough, and most rooms have a couch or armchair that can be occupied by another person. Most people I room up with will bring a sleeping bag as well, should they not want to share a bed.
I suspect the room with a rollaway only allowing 3 people also has to do with safety regulations. Id imagine those regulations are based on available floor space, and with the added bed that floor space is reduced.
I would tell your roommate to bring a cot/sleeping bag. I have never had or heard any issues with using one. If they are really concerned, they should just roll it back up after using it.
