@Martin280 Most here will agree with you. It's frustrating. Although I will say that I have received a 5-star review from someone who never showed and didn't get a refund (so it does depend on the nature of the guest.) I was grateful but good review or not, technically the review was not honest and not an accurate representation of the guest's stay. How could the guest rate the cleanliness, accuracy, location, or value when he never saw it?
I have always said that it doesn't make sense from the host's review side as well. How are you supposed to rate a guest on following house rules and cleanliness when they never showed? Maybe if hosts start rating no-show guests will all 1 star, hindering their chances of future stays, Airbnb will realize the ridiculousness of such reviews.