That's what did at first. Showing the score on each individual review.

But that has implications:

1. You can not surprise the user by letting them use thumbs up/down and then once published suddenly show a score on their review

2. So you'd need a way to display the score in the input form

3. That would show how it changes based on the thumbs the user is clicking

4. They will try to game that

5. Then I might as well let them score it with a number in the first place (which, again, humans are very bad at)