1. 90% of Airbnb hosts are not going to run into that problem because they’re going to do everything to make it right, so to fear it would be akin to being worried about getting hit by lightening.
2. 10% of Airbnb hosts are psychotically delusional and create problems, do nothing to fix them, and empowered by Airbnb, leave the only remaining outlet as off-site reviews. These people don’t have any business renting property.
So that is to say — the “problem” of off-site reviews is a secondary repercussion of Airbnb letting nearly anyone rent their places, and then not doing enough to prune bad hosts out. It’s a fundamental misalignment in their business model to tilt this heavily towards hosts, because hosts have illiquid property in mostly crowded markets (expendable) while customers have extremely liquid capital and lots of choice.