But...unfortunately for him, because of the dumb "hiding photos before booking" policy, he wasn't able to screen out the guest with the inappropriate photo, and now is set up to look like he's discriminating if the guest happens to be a member of a "protected group".
So though he wanted to cancel, Airbnb was telling him they would NOT let him cancel this booking!
We might as well conclude that rude guests who stick out their tongue are also a protected group.
By the way, many of us may remember this host, David, from the hold host community groups on Airbnb. He's been around awhile, and he's had some godawful bad experiences with guests at his listings, so he knows a thing or two about who not to accept.
It may turn out that turning off IB is going to be mandatory for more and more hosts.