Most people don't understand how Rotten Tomato's grades movies.
If the score is 91%, that doesn't mean the average viewer gave the movie a score of 91%, it means that 91% of the people who rated the movie, rated it >60%
Here's another way of thinking about it:
If a movie is rated by three people, 62%, 72%, 67%, then the movie will receive a RT score of 100%.
It's not shitty, its just not intuitive.