I think it can be hard to write a good essay in a vacuum (such as in a school assignment, weeks or months before the app is due. I know my daughter had a class assignment for the common app essay, and whatever she wrote for the class never went anywhere else. In the process of filling out college apps, after the student fills out the info about coursework and EC’s, there is a more of a sense of the overall message or theme that the app will convey – and I think that is when the main essay may emerge. So for any kid with writer’s block, maybe a better start would be to fill out the rest of the common app – (and other apps, for schools that aren’t using the common app).