I believe this issue would be solved if Everyone could see All reviews. You could then easily identify guests with unrealistic expectations, and they wouldn't be welcome into the sweet network of Truly Good Deals that is AirBnB. There really shouldn't be a place here for people who won't even bother to read listings or about the service when they are brand new to it; they seem to be a headache to most hosts. There are many new guests that 'get it.' They are new to service, the look at listings and read up, they see what it's like. Then there are all the ones mentioned in this long thread, which are exactly all that same guest: the one with ridiculous expectations AND didn't do their part up front.
While I understand AirBnB wants to Scoop all the Guests, if you can easily identify the ones that will be trouble, why not just make the whole thing smoother for everyone? I mean really, that or pay for a Whole Lot More Phone Customer Service.
I think honestly there are actually two things that would Vastly Improve both Guest and Host satisfaction in the long term:
When you're new to the service, say until you've gotten one or two reviews... you don't get to leave one. Probably two. Then everyone starts from a place of 'Oh I should be nice' for sure, and it' becomes the standard in the beginning to know you are the one being reviewed.
or 2. Let everyone see all reviews. Let hosts see the reviews guests leave for other hosts, stars included, and vice versa. Nothing bad withers underneath the sunlight right? Let people see how these guests treat hosts on the exit, which is just as important to everyone's sanity in the Long Run.