Credit or non-credit, the quality of any writing course depends on who the teachers are, and how well they match up with the kind of books you want to write.
Good writing courses, meaning ones that do have good teachers, and that match what you want to write, are invaluable. And they're a hell of a lot better than run of the mill betas or writing groups.
Why is it that writing seems to be the only business on earth where new writers assume amateurs who show no indication they can write a publishable book are as good or better at teaching you how to to write a publishable book yourself than long term professionals?
This makes no more sense than a college with no professors wherein the new students simply teach each other, even though none of them have ever done what it is they're trying to teach.
I learned more in six months of good writing courses than in five years of intense study on my own.
"Publishable" is not the same thing as "I like the way you did this", or "I don't like way you did this", or "I'd buy this if someone published it", or even "This is very good", even if it is very good.
Those who have proven they know what publishable is, and have done it themselves, are invaluable teachers, as long as what they've done matches what you want to do.
With some luck, you can find a pro or two outside a writing course who can help you just as well, but if you do, it's still a writing course, still taught by a professional, even if it is less organized.
A good beta can certainly be helpful, but good ones are few and far between, and never a substitute for a professional writer or acquisition editor in your field.
