When you apply to selective colleges, they will want to see and evaluate the records of college courses you took in high school. For home schooled students, this can be helpful if you do well in those college courses, as they will provide some external validation of your home schooling.
Also, college courses that are not remedial (from a college viewpoint) cover similar or higher level material compared to AP courses, so they will show that you are able to handle college level material. In addition, they will show that you can handle actual college courses (with the greater demands for self-motivation and time management than typical high school (including AP) courses).