If he did and AirBnB is just keeping it, shame on them. That's gross incompetence and people should rightly boycott.
If he didn't, he should fix the article to show that in fact AirBnB isn't grossly incompetent.
Frankly, it's a bad experience for the host and guest, which is why I'm not convinced it happens all that often with hosts who have more than zero reviews. If you book a place with zero reviews, I think it's MUCH more likely to happen, as newer hosts are probably less likely to understand how Airbnb works.
I agree that it's not very kind to have the cancellation policy so asymmetric. According to this link (https://www.airbnb.com/help/question/63) AirBnB charges the host 3% to book, probably no matter what.
So it sounds like what they're doing is taking the money that they charged the host and giving it to you. That's nice of them, really. But as you've said it in no way deters a host from accepting a better offer.
I'd be interested to know how you would split the balance instead. Charge hosts a 15% cancellation fee? 50%? I get where you're coming from but I always understood AirBnB to be a part of the "surplus" economy; I can sell a bit of my surplus space for a bit of extra cash. Not a big serious hotel business.
I suppose one option might be to set the cancellation fee equal to what you'll end up having to pay in addition to find accommodations. Of course that'd quickly become a total eff-job trying to figure out what could reasonably be called "equivalent quality" so that people don't get cancelled on and stay at the Ritz.