You have to read it in conjunction with two previous posts. The links were given on the blog, but I will give them again here
The first
http://ocham.blogspot.com/2011/09/masks-at-masked-ball.html links to a discussion on Giano’s page, between a few people including SlimVirgin and Malleus. Slim says “Certain people associated with the Foundation have been saying for years that it doesn't matter who makes the edits; we are all just masks at the masked ball, and what matters is numbers alone. I suspect they'll start to see the folly of that position, though it may take a few years". She goes on “when the history of Wikipedia is written, we're going to be astonished by the small number of people who created and maintained itâ€. Another (Malleus?) agrees that “crowd-sourcing is largely irrelevant, as most articles are edited by very few editors, often only two or three, which is hardly a crowd, and almost all of the content often comes from only one or two editorsâ€.
The next post
http://ocham.blogspot.com/2011/09/who-writes-wikipedia.html mentions a charting tool I developed to examine the growth in articles (in bytes) over time. If crowdsourcing were happening, you would expect to see no sudden jumps in size. Rather, random moves up (as edits stick) and down (as they are reverted), with a slow drift upwards. Rather it looks more like a staircase. A very small number of editors (often only one) produce the article in its final state (although there are exceptions, such as My Little Pony). A further finding was that most of the jumps in size occur before 2008. I forestall the objection that the article had reached its ‘ideal size’ during the growth of 2008. Most of the articles on major novels are small in comparison to articles on My Little Pony and comic books and TV series. Some are more substantial, but that is when someone with a particular interest has written a personal essay on the subject.
You may still ask “whats the pointâ€. Does it matter that most of Wikipedia was built by a few persons, mostly before 2008, and that the building is far from complete? Well, some of us may rejoice. But if I were Jimbo, I would start worrying and try to manage it differently. The crowdsourcing doctrine holds that it doesn’t matter if good content producers leave. There are many molecules producing this upward Brownian drift, someone will soon replace good editors. But if crowsourcing is false, and the product relies on a small number of editors, you would think of ways of retaining them./
That was the point.