BTW, the Uber/Lyft comparison doesn't really work with what Airbnb is doing.
With Uber, Lyft and other de facto Taxi companies, the owner of the vehicle or a representative of the owner is driving the car. At no point, do you take the wheels yourself and drive your own uber. Uber/Lyft while they like to pretend the people who work for them are independent contractors are essentially employees of the company and are usually people's first point of contact.
With Airbnb, there's the potential that you will never meet the person you are interacting with for the apartment room or space you're checking out for the weekend or week. A person could potentially find an unsecured location, place an ad on airbnb, rent out the room for a weekend, collect payment and the actual owner is none the wiser. Is it likely to happen? Probably not, but its one of those things that airbnb isn't checking for and doesn't want to.