Connecting two parties together to rent a place is no problem in general. But the difference here is that AirBNB has, until very recently, been extremely focused on short term rentals that walk and talk like hotels. Most cities ban rentals less than 30 days, unless it is a room in someone’s house or another dwelling unit on their property. AirBNB was great when it was filled with this, but as soon as multi-unit operators took over the site and it became filled with unlicensed hotels that flout the city bylaws, it went downhill and I fully agree that this impacted the supply and pushed negative externalities on everyone else.