Does AirBnB make it easy to view what ratings people have given? Certainly the history of an individual user provides much more useful, actionable information than any broad trait.

It should be easy for hosts to say they only want people with X reviews where most of them are 4-5 stars. Or a better score that weights it based on the host rating (i.e. if a user's hosts generally get 5 stars, but this user rates them all 3 stars, then it's probably a problem with the user, so avoid.) Perhaps AirBnB doesn't want do to this to avoid putting pressure on renters.