One of the elements of the discourse lost in all the shouting over prescriptive language shibboleths is the element of style. A very important style is what I will label stately writing. That is the sort of writing we normally call formal standard written language. The Prescriptivists make no difference in style and level and register; they want everyone to not only write but to speak at all times in the formal standard written language. I recall wanting to vomit when a young person voiced admiration for the way William Buckley talked on his television program, that constant, hollow, stentorian tone he affected with the Oxbridge accent (Did you know his first language was Spanish?) However, for his purposes, that style worked well: he impressed a lot of people and made it clear, by using that style, that he was speaking to and from among the literate and cultured.
And that is the reason for style: to get your ideas across. When the ideas are familiar, a more familiar tone will work if it is appropriate to the occasion. When ideas are new, are expressed in unfamiliar or specialized vocabulary, and are expressed concisely with no redundancy (interesting how redundancy is so important in communication and it is the one thing the Prescriptivists love to ridicule), the style needs to be what I’ve called stately, marching with precision and a smooth but slow pace across and down the page. Since there may already be new terms and unfamiliar locutions, any flippancy, slang, asides, and jocularity should be avoided as distractions.
This sort of writing can not only be well done but also quite beautiful, but that is hard to achieve. When covering the trade negotiations between countries or a business merger or the findings on disease prevention in India, the facts must dominate and give way to beauty, but style remains. “Newspaper style” or “journalistic style” are standard terms for such language but it is found in any expository literature. Its level may be low and the register high, but the low level requires careful attention to explaining the items in the high register which might be unfamiliar to some readers. Frivolity is not welcome here.
Reading that sort of prose should not be a terrible challenge, the whole point of it being to elucidate a topic for the general reader. Writing that sort of prose is another matter entirely, requiring a good deal of editing. Some writers are very, very good at it, e.g. some of our journalist science writers, observers of the society, commentators on economic, health, military, diplomatic issues, and so forth publish best-sellers. Most of the writing in magazines and newspapers is pedestrian but appropriate to the purpose.
And yet almost all the writing instruction done in our schools is geared toward expository prose and even technical writing, despite the attempts of English teachers to get students to express themselves. The focus on prescriptive grammar, grammar which makes no sense to most normal speakers of English, precludes soaring. The plodding, prescriptively correct sentences, one following the other according to a formula, gets the A.
Many English teachers delight in creative writing on the part of their students, but they must face The Big Test where readers go over the final examinations looking for what they deceptively call mechanics. What if the reader reads and absolutely delights in what was written? No matter; if the student makes enough errors in syntax, grammar, spelling, and punctuation, the score will drop low enough for the student to feel his effort was wasted. So what was accomplished? What Frank Smith says: the student does learn, learns that writing is hard, boring, and unrewarding. So many wonderful books have been written by teachers praising the diary and journal writing of their students, of the creative writing, and often dramatic accounts of difficult lives. But that part of it seldom enters into the grading process, at least at the “final” level. We get back to mechanics.
So how to bring student writing in line with formal written English, expository style, creative writing using punctuation? First of all, never introduce them to e.e. cummings. 
Next, have them read, and read, and read, and read……… and read stuff that is truly fascinating to them. That means big libraries, lots of books piled up in the classroom, and lots of time to read with no purpose, direction, or assignment. Out of that, reaction journaling can begin. Jim Trelease and Stephen Krashen are big on providing students with lots of reading in their early years. High school is very, very late. Some people start reading then and go on to write well, but not enough to justify waiting until high school to let students read “stuff they like”.
What prevents us from developing good writers, and by “good” I mean competent, not gifted. First of all, few Americans read. Second of all, few Americans write. Third of all, writing is considered a special activity which must be done “the right way” and sound a certain way when read aloud. Fourth of all, writing is considered the province of certain kinds of people, not everyday people. Fifth of all, a stern approach to writing focuses on expository and technical writing with little patience for humorous, flippant, dramatic, experimental, or creative writing. Sixth of all, few teachers in the lower grades are prepared to teach writing; they get as hamstrung as most adults and think good writing means is equivalent to answering the phone, “This is she.” Seventh of all, a large number of people in the general public sit like vultures on the limbs of their local outlets, waiting to pounce on a teacher’s “illiterate” note home or an advertisement’s use of an apostrophe. And so on…………