While I think you are absolutely correct in your position, we must as well defend the right of guests to temporarely live their chairs for any kind of reason(s)...as example they forgot one of those celebrity gossip magazine in their room and they just need to go to pick it up, or they have some phone calls to do and do not want to bother fellow guests with their noisy chat...there might be tons of reasons.

I believe the best policy I had encounter is to clean any chair/bed that is let for a maximum time of one hour.