Because Airbnb is willfully provide full refund to Guests - even after staying 1 night, and with their complain = general opinion such as uncomfortable, feel unsafe, small, not clean, too cold, too hot, not enough this, not enough that, etc.. it's spread amongst the cheating Guests, that just book for a minimum of nights, come and have gathering/party, and stay for 1 night, then complain the next day, and then leave - with all trash behind... then get full refund.
A nice clean venue, good place to shower/bath, good place to sleep, and not even have to clean up afterward. All free, using the approach above. Words have spread out amongst the cheaters/abusers....
Airbnb willful to refund to Guests has spread the word that Airbnb indirectly will support and encourage this bad behavior, i.e. cheating and abusing hardworking Host and impact their income.
I have experienced this 2 times in 2 months.