Remember, Airbnb is a marketplace so it is your responsibility as the guest to clarify the exact sleeping arrangements. If you want a higher level of service, go to a hotel. You'll pay a lot more, but if you require great service then it's probably a better option.
One isn't likely to clarify that with the host prior to arrival given that it's on the listing. AirBNB needs to take responsibility for this kind of thing given that you pay about 15% as AirBNB fees and 3% is also paid by the host. Refunding just the fees isn't what you pay the fees for. It is to take care of situations such as this.
That field is mostly useful for distinguishing between whether you're getting a couch or a bed in the case that you're just renting part of the apartment. It's not very useful in the event that you're renting a whole apartment. It means there's at least one real bed, it doesn't mean that everyone in the "Accommodates" number will get a real bed.
It's not perfect, it would be better if it were more explicit, but this is a pretty common on these sorts of listings.
AirBNB fails on both accounts.