I think that that would be great. Don't over do it though. Passion and determination are great if you have some good credentials and experience to back them up. Remember they want to see all of you, the "whole person."
I think that it would be a great idea to have. Because everyone always says that service academies want their cadets to be self determined. I know when I do mine that I will put something like that. But same of what Bsa07eagle put.