I found Christiane to be an extremely difficult guest.
Anyway, the overwhelming majority of guests staying are not reporting "unbearable" noise (over 99% of the 500 or so guests who have stayed over the last 4 years have not raised this as an issue).
The floors - when large groups (9 or 10 guests) walk in and out of the apartment with shoes all day, they bring in dirt on the floor. We clean the floor thoroughly before your arrival, but the floor does quickly get dirty again.
It was not Airbnb who found an acceptable solution here - I agreed to refund Christiane, because she was apparently so unhappy. Airbnb gave me the choice.