>It's well known that negative reviews are scrubbed and even edited
If this is true, then I see no other blame than Airbnb themselves. If you make a platform allowing reviews in such a way that the "seller" can edit the reviews "users" make, then that's never going to become anything other than scammy. Even allowing a review to be scrubbed/removed by the seller is bad. There should be a mechanism to work with the platform to handle fake/false reviews, but the seller should never be able to do that on their own.
They have a long list of things you can't complain about. One example is things that the seller can't change, like a loud train nearby. At least when I last used it if a single sentence in your review violated one of those policies your whole review was deleted and you couldn't submit a new one.
Interestingly their dispute process is very buyer-friendly, though. When a seller demands money in compensation for damage they often lose. I believe this is because Airbnb is on the hook if they can't collect from the buyer.
If this is true, then I see no other blame than Airbnb themselves. If you make a platform allowing reviews in such a way that the "seller" can edit the reviews "users" make, then that's never going to become anything other than scammy. Even allowing a review to be scrubbed/removed by the seller is bad. There should be a mechanism to work with the platform to handle fake/false reviews, but the seller should never be able to do that on their own.