@Chris232It is most unfair to penalize hosts for the guests failure to review the host. Seems to me, the most fair way would be to require hosts to review guests and guests to review hosts. Perhaps not allow any booking, after one has say 3 NO reviews? Or preventing further bookin until one goes back and actually reviews the host or guest.
I have known way too many people say that they left no review, as they really did not wish to leave a bad review for a host or guest. There could be lots of guests and hosts who could improve, if they had accurate reviews. It is unfair that hosts are punished with bad guests, because some previous hosts refused to leave a bad review and vice versa.
It is possible that if Reviewing is enforced somehow, then the overall scores may drop. Or increase. Ok, probably drop, but then perhaps we would have a better gain on how a guest or host would behave.