i have a high school diploma and only audited university french and italian courses at the age of 39-40... yet i had a successful writing consultant business with clients paying obscenely high fees [up to $150/hr back in the 80s!] for my writing and editing skills... i also was paid to write columns for magazines and newspapers, was a salaried editor of a regional magazine, and had a rather wide variety of my original works commissioned for pay and/or published for pay... i think that proves the point that if one has the requisite talent and ability/skills, one does not need to go to college or acquire any higher education degrees to succeed as a writer...
I think it was mentioned earlier in the thread, but what college education gives you isn't a better command of the language. (In my case it did, because I'm Eastern European, but I'm in the minority.) As both John Gardner and Samuel Delany have pointed out, college provides an environment where the main point is to learn; learn from people with viewpoints different from yours, learn from people that know more than you, learn from people that know less than you - who mainly teach you whatnot to be like, - learn from large libraries which are freely available to you. Almost no other environment focuses on discussing stuff, and that's absolutely crucial to gaining the outlook that would give one the mindset to write fiction that's not bland, dull or sound like it's written by a malicious and/or idiotic crank. (I know one such guy that had no college education and in his early 20s came across some Fascist literature and Books of Theories. Yes, he's read tons of books. Most of these are utter crap and so is his writing. He simply lacked perspective.) I think that's even more important now, because a hundred or even fifty years ago people liked to read and read a lot, college education or not (Faulkner read and re-read Keats during his night-shifts). Nowadays I come across writers inspired exclusively by TV, cinema or video games (!?), who only write because it "costs nothing (!?!!?!) and I got stuff in my head I wanna get out". Writing is rigorous stuff and it requires rigorous thinking. Alt+Tabbing Wikipedia Articles doesn't do that for you, neither does it help you improve your attention span. Yes, you can learn rigorous thinking outside the college environment, but then you'd be swimming against strong currents. Did you know what Shakespeare topic prevails among well-read non-college (in some cases non-humanities) educated people? If he really was Francis Bacon and if the Friend from the sonnets was his gay lover. Most of them haven't read the sonnets or anything else by him for that matter.
Not all non-college educated people are dolts. Frankly, I've had much more intelligent conversations with people who didn't attend college than those who have. College is not going to make someone a better writer. That is entirely up to the individual.
This seems to be the perennial question. But for me too much structuring, as in studying writing with schools and universities, will most definitely serve to 'cramp my style'. I always felt that way, intuitively, and relied mostly on my 'creative juices' to get the writing going. But I must emphasis, too, that the study of grammatical usage, the expansion of adjectives, a good thesaurus, and the right punctuations are very important in the anatomical structure of any story.
I think one thing that should be required for writers who are looking for more than a high school education, is a course in philosophy, creative & critical thinking. Free, book course or certified courses, doesn't matter. Something to make you think like your character/world. Something that will help you create characters/worlds worth remembering, But other than that, its up to your idea of success, that will determine if a higher education will motivate you to become a published author.
I did a creative writing and philosophy degree. The writing part opened my eyes in many ways, 3 years of constructive critiquing of my work and being forced to read literary fiction and then analyse it from a 'writer's craft' point of view rather than the themes and englit point of view. This was incredibly valuable to my development. It is something you don't need a degree for of course, but all the same, a course that forces you out of your comfort zone in terms of reading, of forcing you to look at the mechanics of writing, can't hurt.