No doubt such a system would be a huge privacy problem for people as people would say that negative reviews reveal their private facts, or that those reviews are defamation.
However, if the network is decentralized, then it might be possible to keep it running even in the face of opposition from state actors.
If we have a peer-to-peer rating/reputation network in place, it would allow people to bypass the elitist inside networks (old boys clubs) to raise capital from investors based on mass positive reputation.
Rascals and scammers like these failed Kickstarter bros would be shut down after a single scam ... they would not be able to rent or scam another person after a single scam.
Implementing a centralized reputation system would be a good first step.
I understand why Yelp and other established companies don't want to be in this business. Its a liability/privacy nightmare.
Imagine the first time some innocent girl in high school is unjustly called a slut, and is defamed by her own school as part of some bullying clique.
I believe the network can ameliorate if not outright prevent such clique abuse by enabling users to rate reviewers based on the reviews they have given. If you abuse people with your reviews and ratings, it can damage your own ratings.