Airbnb already served its purpose of connecting, but after we are connected, it has done its job and got paid for that—everything that happens next is private, and nobody needs to know anything, but many people don't understand the meaning of public and private...
I have never hosted on Airbnb but I assumed there was some kind of liability insurance made available when using the service. I think this is a very plausible and reasonable justification for hosts to want to continue using the platform for providing rental services