The problem is that coherent vision and
a prior design are NOT equivalent. Obviously, I cannot know what was going through the head of ESR when he wrote the original essay, but what I've always taken from it is that
a priori design is inherently inflexible, prone to becoming disconnected from reality, and ultimately less inviting to creativity.
If the suggestion of the article is that the only way to retain quality is to move back to the "single vision" world of a priori design, I'm sorry...that ship has sailed, the cat is out of the bag...whatever your favorite analogy, PHK is very right that the new generation has gotten used to not having instructions handed to them.
Of course, anyone is free to start a project with a single vision, recruit new members, and do their best to grow the project. I suspect, however, that such an effort would loose out to one that figures out how to develop a coherent vision without the need for a priori design.