Nosedive would never work in real life

It think it would match what we see with the way finances are skewed today. Eventually most would either pool in the fours or the ones with not much in between.

Maybe it could work if only people with a score close to or higher than yours were able to rate you. That way, people who just *beep* with the system become paria's who can't really mess with the high scores, and the high scores keep the system in place.
This would be a logical feat, since high scores already get special treatment (for example; Lucy's told she could get 20 percent off the price of the house, if she scored a little higher).

The system would be intelligent enough to atop people abusing it. Maybe it would only allow you to give so many 1 starcratings each day and never to the same person twice. If could even damage your own rating by giving too many 1* ratings since its obvious you are trying to abuse it so it could penalise you And put you on double damage.
If you rate someone 1* on social media they can see your acore and they will rate you 1* back and soon you'd be in prison.

Also when u rate someone after and interaction or soneone close by they can see that they've received a low rating so it wouldn't be long until people found out you were giving everyone low ratings abd you'd loae your job and mayb go to prison.

You would end up being a low quality user then, so your down votes wouldn't matter. It is troll proof in that way. Trolls don't have be patience or grit to actually put on a fake face outside to make everybody love them.

I think it wouldn't work for the simple fact that you can't hide your scores against other people. Many would be too afraid to give a low rating rating out of fear of confrontation.

If that's the ONLY problem you see with it.....

You must never have used eBay or Uber.

It already works in real life. Buy something off eBay, people will lose their mind if you don't give them positive feedback. Uber drivers are better than regular Taxi's because they treat you nicer to avoid getting down rated.

What you don't realize is that your eBay or Uber rating already disqualifies you from things due to the attached personal information and fraud risk scores. If you have a bad eBay rating and you try to open a new account, forget it. If you had an eBay or Paypal account while they were one entity, that is also attached. Likewise for Skype.

The issue is that private information is often not "sold" but "acquired through mergers and acquisitions" and then "divested" at other times. Those Privacy Policies mean nothing, and people should oppose companies merging because those companies have unfettered access to your private information.

But let's focus on the "rating people" itself aspect. This function already exists in Facebook and Twitter, it's called "liking" peoples individual posts. What eBay learned back in 2007 or so is that people use negative feedback for punitive reasons, which is why "rate 1 to 5" should not happen, because people will rate people a 1 to spite someone, even if they've never met. Take for example the Hillary/Trump election. Millions of people would rate them a 1 just to express their displeasure with them as a political options, regardless of having no personal interaction with them at all.

Which goes back to the OP's point, it would never have a practical way of working as long as you can leave negative feedback. You should only be able to leave "Like" or refuse to leave a like. When someone leaves a like, you don't leave a feedback trail either, it only changes the score and never removes a like once left unless the 'liked' item has changed.

So yes it already exists, but the reliability has proven to be not be effective because people are petty.

You are defective .... please get fixed or remove yourself.