Not really. There's a difference in terms of marketing when a movie puts "93% ON ROTTEN TOMATOES!" on their commercials compared to "7.3 ON ROTTEN TOMATOES!"Nah, the percentage is the better way of doing things. It gives people a general idea as to whether the movie is worth seeing or not. It's fine as is.
It's deceptive and that's why studios use it for marketing.
EDIT: Holy shit, RottenTomatoes now hides the average rating behind the tab, "more info". Fuck Rottentomatoes.