Back in the late '70s, Jim Cornette was reading the TV Guide and talking on the phone with his friend Norman Dooley. Dooley distributed a self-published wrestling newsletter in the Louisville area, which included the results of matches he attended live. In addition to said results were Dooley's editorial comments, including assessments of match quality. Facetiously, Cornette remarked to Dooley that he should include star ratings like the ones that were next to the movies listed in TV Guide.
Dooley took Cornette's joke to heart and began rating matches on a four-star scale. Soon, other newsletter writers implemented this practice, including a young Dave Meltzer.
At their most innocent, Meltzer's star ratings are just one man's opinions of a subjective medium. At their most constructive, they're a handy way of cataloguing some of the best of wrestling history through the lens of an experience tastemaker. Twitter user Allan Cheapshot has an incredible ongoing thread looking at every 5+ star rated match, and it's a wonderful dive into the evolution of what has been considered "great" in wrestling.
But seeing as how Dave is a polarizing figure, so too are his ratings. Whether it's rating a match too low or too high, there hasn't been a shortage of time a large, vocal section of fans have given Big Dave grief for his grades.