Be consistent in scoring, and tell me why

I thought I was having good holes until I saw one of my holes has an average golfer score of 5.5. I thought scores were out of 5? (the 'review' score is 5...)

What is the avg. golfer score out of? How do I improve it? And why does a high score have a low "thumbs up" rating? How do I improve that?

I have an A+ hole with a 5.0 but 24% thumbs up, another is A, with a 5.5 score but 13% thumbs up. What makes these better or worse? How do I get hole-specific feedback?