Trustworthiness of the Airbnb rating system

In the Airbnb system renters require a high rating from there hosts in order to be able to rent quality units in the future. Host require renters provide them a high rating so that their rental units show up in searches and popularity, integrity in Airbnb websites.

At 1st glance many might miss the conflict. Both guest and host are forced to obtain good ratings. Imaging the pressure on the guest who is unhappy with the state of the rental unit, perhaps it smells like mold or has very bad neighbours, if this guest complains, does she run the risk of obtaining a bad score from the host? That would reduce her ability to rent from other better-quality hosts in the future. Any squabble on site will have both parties wondering about there star ratings. In fact, it’s common for hosts to mention the rating system in a squabble with guest.

The question is as a guest; “Are you willing to jeopardize your good rating score in order to poorly rate a host?” With the most common answer being no, how accurate is the Airbnb rating system?