We recently stayed in an Airbnb in Miami Beach. It was pretty clear that most of the building was Airbnb rentals. They were small condos on the beach that were ideally suited for it. It would suck to live in a unit in that place. I'd probably move out and rent it too.
I just read this shitshow of an incident and article that brought up some other issues with Airbnb, but provided no real solutions.
I stayed in Airbnbs for all our travels in Europe. That's 3 nights in Budapest, 4 nights in Greece, 2 nights in Rome, and 4 nights in Marseille. Grand total: $663.00 for 13 nights or an average $51/night. All centrally located where comparably hotel rooms would be $100-$300+/night.
Budapest - a young couple with a newborn. They each had their own place and when they moved into a new place together, they each kept their old studios and rent them out on Airbnb now.
Athens - A older couple own a four unit building that is a 5 minute walk from the Acropolis. Their daughter and son in law rent out two of the units on Airbnb and stay in one of the units when they are in town (which is rare). The older couple lives in the ground floor unit and grandma has her rooftop unit / garden.
Rome - A guy from Russia obviously lives in this place for some part of the year. He has a few locked cabinets and his daughters toys and clothes in a playpen in the corner. He has expensive DJing gadgets and a very nice piano in the apartment. I believe he spends most of his time elsewhere though and rents out his huge unit on Airbnb. He has a partner (business partner) who drops off keys via scooter.
Marseille - Guy obviously own numerous studios around central Marseille, all of them in newer units. Lightly furnished exclusively by Ikea, no signs of "homeliness" and more like a hotel than any other unit we've stayed in.
We also used them for Curacao.
The reality is: Airbnb is great for tourists, great for owners, and shit for locals. Nothing will change that. The points San Francisco has made about their effects on the local housing market are dead on. It's part of a larger issue with the housing market (especially in San Fran) but Airbnb is part of the problem.