I'm not sure that a standard homeowner's insurance policy would pay out in a case such as this. Airbnb is putting hosts in the position of a business; one of the services they could (and should) be providing is some form of insurance (for an added fee, of course.)
Just because homeowner's insurance doesn't provide this type of coverage doesn't mean it doesn't exist. It may be a good idea for Airbnb to attempt to provide this type of coverage. However, whether they offer insurance or not does not change the fact that the risk is the host's to mitigate.
