Earlier quoted context omitted.
Even in the US, I don't know many friends with enough living space to have an entire spare guest room. When friends visit, they sleep on the living room couch or an air mattress. Is this not typical?
I think the operating word here is not "mattress" but "kitchen". How cramped do things have to be to need to put the guest mattress in the kitchen ?
It doesn't seem that crazy that there would be very little space. Visiting parents and/or grandparents probably got the bedroom, some friends the living room.