In large numbers, yes, it's hard to spoof a good/bad rating. But the mode/median of review numbers is likely to be easily game-able (like 20 reviews, for example).

Furthermore, if your property gets too many bad reviews you can either rebrand (expensive) or just create a new property description (this is what happened when my sister found a screw in her food - the restaurant retaliated to her Yelp negative review by just creating a cloned restaurant listing then spamming that listing with positive reviews).