It's true, she could have. But many famous people donate to charities...their life isn't exactly made heroic by that fact. When you have billions of dollars, to donate millions doesn't hurt much. It can be good PR and keep your name in the papers but it doesn't necessarily make your life honorable. A drug addicted singer isn't quite on the same par as men and women who sacrifice their very lives for their country and their fellow men.
Drug addicts come in all walks of life ~ in this case, a singer who did alot for her community. What's wrong with honoring that?