I would imagine that homeowners being terrified of having their homes trashed by guests would also cut into their revenue stream, and, if the "97% of airbnb guests are wonderful people" bit is true, the premiums should be fairly negligible.

At the very least, it should be an option for property owners to purchase.

Even if you do have homeowners / renters insurance, I wouldn't be surprised if most policies have exclusions for operating your home as a rental.