Contrary to all schools of art and esthetics, writing is something one can learn. There is no mystery about it.
In literature, as in all the fine arts, complex premises must be set early in a person's mind, so that a beginning adult may not have enough time to set them and thus cannot learn to write. Even these premises can be learned, theoretically, but the person would have to acquire them on his own. So I am inclined to say that fiction writing — and the fine arts in general — cannot be taught. Much of the technical skill involved can be, but not the essence.
However, any person who can speak English grammatically can learn to write nonfiction. Nonfiction writing is not difficult, though it is a technical skill. Its only difficulty pertains to a person's method of thinking or psycho-epistemology. What you need for nonfiction writing is what you need for life in general: an orderly method of thinking. If you have problems in this regard, they will slow you down (in both realms). But writing is literally only the skill of putting down on paper a clear thought, in clear terms. Everything else, such as drama and "jazziness", is merely the trimmings.
I once said that the three most important elements of fiction are plot, plot, and plot. The equivalent in nonfiction is: clarity, clarity, and clarity.