After watching some videos of what Uber drivers have to put up with, as well as having a few friends that work in retail, some kind of "social metric" may not be the worst thing.

As a society, we put up with a lot of terrible behavior and people get away with it because they don't care about making a scene or situation that is uncomfortable for everyone else. We pay higher prices to deal with these people's behavior: constantly complaining until they get free stuff, abusing return policies, review blackmail, vandalizing state/national parks, cutting lines, etc.

You're right though that we need very strong guarantees around the sources and accuracy of such a metric.