I doubt people would make these booking if they were fully aware of the risks. The fact that the product exposes its customers to glaring risks should be a serious issue and it is upsetting that the company is just throwing up their hands at the issue. Some thought:
1.) A refund doesn't make the customer whole. If there weren't an arbitration agreement then I would expect that a court would expect more than just a refund. There are travel expenses, there are last minute booking fees. The customer had reasonable expectations of having a place with a core set of features for a specified duration. They need that and airbnb should foot the bill (which is typically higher than just a refund due to the last minute nature of the problem).
2.) Banning scammers is not enough, airbnb should take legal action. As mentioned a court would find that this scam costs the customer and the platform a lot of money. Well Airbnb should make it a point to punish scammer and the courts are the proper medium to take action.
3.) They should audit listings. If someone is making ~$2-5k a month on a rental and airbnb is taking ~3% or ~$60-$150, they could easily afford to send someone out to visit the unit, check the boxes and write an official verified review.