@Leli64 Hosts have been jumping up and down about the unfair review system for a long time and Airbnb has chosen to ignore that. Airbnb actually tells guests that a 4* rating is "Good". They don't want to let guests know that anything less than a 4.7 average is something they send hosts warning messages about.
So all hosts can do at this point is let guests know how the ratings are applied on the host end. There are various ways to do that without being crass and teling a guest to give you a 5* rating. There have been several threads on this forum where hosts discuss how they do this.