Looking at the babyfaces in the pic on the airbnb ad, my guess is that it wasn’t the owner who put it up, it was the owner’s son. If you own a 20 mm mansion, you don’t need to rent it out by the night to pick up a few ducats. I bet mater and pater are in the south of France for the summer, and junior thought he could make a little spending money the easy way.
Best explanation I have heard.