This is wrong in so many different ways it's like an art piece. Every part of it that tries to defend the central thesis is actually disproving it. It's kind of funny actually. Here's a dude that's been writing for 30 years, and not only is his writing bad, his ideas are crap. It has the feel of somebody who's completely convinced of his own ideas, despite the fact that they're based solely on his personal experience.
I have a simple proof that the thesis is wrong. Take a moron, and have him work on a farm for 30 years. Then have him write a book about running a farm. Now, he's going to sound like a moron, and will write very poorly. But most everything he writes will be right. Despite his bad writing, he can still communicate his observations of how and why simple things work. So it's not hard to be right while sounding wrong. You just have to be a moron.
I don't think your proof works. Here is a line from the article where he elaborates on what he means:
> By right I mean more than just true. Getting the ideas right means developing them well — drawing the conclusions that matter most, and exploring each one to the right level of detail. So getting the ideas right is not just a matter of saying true things, but saying the right true things.
I'm guessing that a moron with 30 year's experience on a farm would not successfully do that, even when writing a book on farming.
Even a moron can write directions for how to milk a cow. It doesn't matter how poor the writing is, it matters whether a person understands it. People can (and do, regularly) understand poor writing. Even a child can write its parent a note expressing love in terrible writing that the parent will understand, and the idea remains right and true regardless of the quality or style of writing.
Historical recipes are terrible because they lack details. They don't tell you to add salt, they don't include accurate measurements (of temperature, time, ingredients, etc), they don't explain methods. Yet people of the time they were written can still follow those recipes and cook the intended dish. Writers always leave out details that are assumed by the reader. At the time those recipes were written, those people reading them would have already known all the left-out details.
If I write you a book on programming, I'm not going to explain to you what a computer is, how it works, how to copy software onto it, how to power it. You're going to already understand all that, or you probably wouldn't be reading a book on programming. Depending on what you understand, and depending on what ideas I try to convey, and how I do that, may change the end result of the information you come to understand. But they don't make the ideas less or more valid because I wrote it this way or that way.
Writing is only the communication of an idea from an author to a reader. Style, form, method, construction, etc are all inherent to writing. But the validity of the expressed idea is not. The content of the idea is completely separate from the "art" of writing. A painting of a blue sun does not affect the sun, nor does a painter's ability to depict the sun affect the sun. But a bad painter can still paint a bad painting that a viewer will understand to be the sun.
"Good writing" is like "Good art". It's subjective. As long as the recipient got what the producer intended, it's good enough.
I think the the essay is largely about exploring ideas deeply. And in much the same way a chef might stress that you must add the eggs one-by-one or whatever other culinary unfounded superstition they employ, your farm moron will stress always plowing east-to-west or something---both processes may yield a perfectly fine product, but neither has actually understood what's actually going on. They may be expert practitioners, but they are no experts.
I have a simple proof that the thesis is wrong. Take a moron, and have him work on a farm for 30 years. Then have him write a book about running a farm. Now, he's going to sound like a moron, and will write very poorly. But most everything he writes will be right. Despite his bad writing, he can still communicate his observations of how and why simple things work. So it's not hard to be right while sounding wrong. You just have to be a moron.