For a gymnast to be successful, she needs to strike a balance of everything within herself. She needs to be graceful, flexible, perform all elements, turns, maintain co-ordination - she has to have all of that. If, for example, she only has co-ordination and nothing else, she will not succeed.
Some of the authorities would like to remove rhythmic gymnastics from the list of Olympic sports and turn it into art. I think this would be wrong, as rhythmic gymnastics is a true sport - we train around six hours per day and sometimes spend entire days in the gym.