It seems as though he's in the right, and that AirBNB is still screwing him over, so why mention those things?
The AirBnB Tenant screwed him over. Why would AirBnB have any responsibility over the tenants?
Because there's a person in between there. The one at fault is the murderer: the man holding the gun. NOT the gunsmith.
Similarly, AirBNB is not responsible for the tenant's misbehavior. What am I missing here?
They may not have any legal responsibility.
But consider the message sent to potential renters. Does AirBnB really want this horror story out there, scaring away customers?
In the end, AirBnB's message has to be "we make renting to strangers safe" or else nobody would rent with then. But a lot of people in this thread are saying "he took the risk and paid the price". So which should a potential renter believe?
It also implies if he had a snowball's chance in hell of prevailing in a lawsuit against AirBNB he'd have filed it.