Presentation
The presentation of an essay is important because points are gotten for good presentation. There are no rules for good penmanship, but there is no time for sloppiness when taking the SAT essay section. Using crossed-out words, arrows and other markings on the essay will sometimes end up in the subtraction of points off the total score.
By showing care for ideas and having a game plan, it is easier to present the essay better which can lead to a much higher score. Making it easier for those who grade SAT essays can help improve the chances of a higher score, so presentation is important for many different reasons.