These experiences are becoming increasingly common, I think. I recently had a guest who contacted me hours after check-in, telling me that her friend didn't feel well so she wasn't coming up (she had booked the place for one person) and we had been in contact the week before her arrival. I think she didn't come up because the weather was cold and rainy.
I told her that she had to cancel herself, which she did, but then requested a full refund. My cancellation policy is moderate, and she wasn't refunded anything. She then went crazy and phoned me multiple times, had AirBnB call, etc. Happily she threatened to leave me a bad review in AirBnB messaging, so I was able -- miraculously -- to have her ferocious review and 1 point removed.
I tell this story because SHE HERSELF WAS AN AIRBNB HOST! I can only conclude, therefore, that she fully understood how vulnerable we are to extortionate revenge reviews. Happily in her fury she gave a clear example of extortion.
My thought for this thread is that, faced with this bad behavior resulting from AirBnB policies favoring guests, hosts just have to band together and say NO. We will ALL initially get revenge reviews, all our ratings will go down, and that will be just fine. In the end, guests will understand that we are operating a business and not a charity for well-off people who have been spoiled for most, if not all, of their lives.