Hi there,
We run a successful Airbnb and have feedback about ratings.
The issue is the understanding and expectation of ratings in Airbnb. The hotel industry has a well defined and established ratings system. 5 stars means something really exceptional and you pay for it, usually much higher than 4 stars. In most travelers minds, 3 stars is good, 4 stars is better (when I travel I usually choose a 4 star hotel for a bit extra and it is excellent. I do not travel 5 star as it is really expensive and I can live without all that extra luxury. Now when we ask guests to rate an Airbnb, some especially the older demographic think in these terms.
So for example, I had a couple stay with us and they were very happy with the experience, gave a positive review and even booked again the next year and they gave us 4 stars. To them we are not a five star hotel and they are right. The problem is that in Airbnb land, 4 stars is a negative. When I get 4 stars I think, what did we do wrong! Isn't that terrible. This is because unless you maintain exceptionally high ratings you lose your superhost status and possibly your place in search results. I really believe this ratings system needs an overhaul. 3 stars should be the base, 4 stars should be very good or excellent and 5 stars should be reserved for something truly exceptional. Same for rating guests but watch the storm is you downgrade a guest in the current schema!