I agree. Sooner or later we will all run into someone who gets a thrill out of destroying a perfect record for no legitimate reason.
If the host provides a reasonable answer to a guest’s complaint the negative review should be stricken from the record.
Since Airbnb refuses to arbitrate disputes perhaps we, as hosts, should be able to elect a council of superhosts to act as an arbitration board, with the power to lift suspensions and discredit destructive guests.
If Airbnb continues current policies I see a massive class-action suit coming. False, malicious and damaging reviews constitute libel, and if Airbnb encourages the perpetrators and provides a platform for their vitriol they may well be civilly liable.