For 30 years before becoming a mystery shopper, my husband and I worked for a publisher selling advertising and rating campgrounds and RV parks on a 1-10 basis in 3 different categories. We walked a very fine line with ratings because we had to sell the ads to the same companies. Many customers would not commit to advertising until they knew their rating which was reviewed and updated annually.
Over the years, however, we learned that ratings were very often a matter of perception. We also trained newbies in the field with guidelines that were 3 pages long. After telling one new couple about this, they asked 1 camper how he liked the park we were in and if he felt the rating we gave was accurate. He said it was great and was planning to return asap and that he felt the rating was too low. A few minutes later they asked another camper with the same basic demographic what he thought. He said he hated the place, thought it was a dump, was leaving asap, would never come back, would tell his friends to stay away and that it should be deleted from any list of parks because the rating should have been a 0.
RV parks always claimed their best advertising was word of mouth. So our comeback would be that they would have to protect against the 2nd type of unhappy camper.
Anyway, long story short, any rating system, no matter how subjective, specific and well-controlled, is inherently flawed because everybody's needs and wants are different. Plus, on any given day, those needs and wants can do a 180 because of some little unexpected thing that sends us off into left field.
That said, if someone wants to start doing a rating system, I'll be glad to add my input.