Writing for their lives vs. writing for the SATs

I found Mahiri and Sablo's article, "Writing For Their Lives: The Non-School Literacy of California's Urban African American Youth", interesting, insightful, and frankly, depressing all at the same time. I found the research that they did to be fairly comprehensive, and enjoyed the work of the students Keisha and Troy. The article speaks to the students tremendous ability to understand, organize, and creatively put on paper the main issues and achievements that surround the students' everyday life, but at the same time, it also addresses the students' lack of enthusiasm for in-school writing. It presents the disconnect between the literary discourse often found in a school curriculum and the relevance this literature actually plays in a student's everyday life. Many students in general do not like to write, and it is seen in this article that even Keisha and Troy, who do enjoy writing and do so voluntarily, do not like to write in school. This, in my mind, is the problem. It is great that these two students want to, and can in a creative and proficient way write voluntarily, but I can't help but wonder, how long can and will this voluntary writing actually be enough to be considered "writing for their lives"? At some point, in order to continue in higher education, or often to even get a higher paying job a standard must be met. There is a level of academic discourse that is expected of those heading into higher education. Now obviously students like Keisha and Troy are proficient and creative writers, so is the problem then in the standard set by the institutions in expecting a specific style and way of writing, or is the problem in the students' lack of desire to modify writing essentially to the test?
I know that when I was growing up and learning to write, I, like everyone else, felt that I had my own personal style. I enjoyed writing and considered myself to be good at it. However, when I got to high school I felt that the writing expected of me was so structured and mechanical that there was no longer room for my personality. I knew what was expected of me to get by and have now mastered formulating standard papers, knowing how to write them in just a few hours. I know I will do ok on them, but that they will be nothing special, nothing I am truly proud of. So that to me is the dilemma: how do you let a student have a sense of ownership and creative style in his or her in school writing while still achieving a standard level of writing that academic institutions expect?
For urban African American youth Mahiri and Sablo suggest connecting the literary curriculum to those subjects relevant in the lives of the youth. They also suggest that this can only go so far, and that bringing these subjects so openly into a classroom is difficult. From what I took from the article, the goal is to relate to the students and then hope this lights some sort of writing fire within them. The question is how, and even then, will it really work?
Going back to Keisha and Troy. Their voluntary writing is an example of writing for one's life, but if they cannot find success in their in-school writing then what? And as for the other students who do neither voluntary writing nor in-school writing, is trying to relate to them and encourage them to write in high school simply too late?
I would consider myself an idealistic person, but this blog almost reflects my stream of consciousness in reading this article, and represent the questions that are baffling to me.