if you win the olympia once, they just keep voting for you. arnold, dorian, lee, lenda, cory - i believe they all won more than 5 times. and now ronnie.
i'm not saying he isn't big, and i'm not saying his physique isn't mature and symetrical - but there are some other REALLY great bodybuilders out there. arnold beat serge oliva more than once, and many people felt that was silly - serge had a denser and really classic shape, and more muscularity than arnold at the time.
http://www.ifbb.com/halloffame/