What do you like so much about this article? What makes it excellent? What qualities of its analysis particularly appealed to you?
What I read was a piece that centered on a single --- and I thought dormant --- controversy about the purpose of Wikipedia: that, because the marginal cost of a new article on Wikipedia is zero, its charter should include comprehensive character-by-character breakdowns of fictional works. Not just of Pokemon, but of every fictional work in which its editors have an interest.
Reasonable people can disagree about this. But it's not the sweeping indictment of Wikipedia I'd expect from this comment thread.
The article offers two empirical studies to support its argument that deletionism is harming Wikipedia. In the first, it collects the "External Link" contributions of an anime-focused editor and records the (very small) percentage of proposed links that were ultimately accepted into the bodies of articles.
But the links he's highlighted appear to be of very low quality. I clicked through a random 10 of them, and most of them were 404'd. The ones that were alive all appeared to be UGC online reviews of individual episodes of anime films.
I'm not surprised that editors who watchlist anime titles were reluctant to stuff articles with tens of links to individual "mania.com" review articles (none of which appear to live today).
In his second experiment, Gwern selected a random set of Wikipedia articles and killed existing external links, to measure how long it would take for them to be restored. But by his own admission, the process of selecting random articles meant he was working primarily with articles nobody cares about. He suggests in the text that the median number of users watchlisting the articles he tampered with was 5 --- but links to the Wikipedia editor who informed him of that without noting that 5 is a very low number; by comparison, the Wikipedia article on Paul Graham (once notable on HN for being put up for deletion on WP) has over 125.
But the bigger flaw with the experiment is that it misconstrues Wikipedia's position on external links. The WP:EL policy Gwern cited in his external deletions is direct about this: Wikipedia is not a collection of links. The project does not view sprawling collections of "External Links" as a good thing: what it wants are links to reliable sources that back up points made in the prose article itself.
It's no wonder that article watchers didn't rush to add links back to stories; the links that he removed were marginal, at times totally disconnected from the stories themselves (as with the "nsplacenames.ca" link on Rockingham, Nova Scotia), or dead (as with the video link, unreferenced by the article, on the Shahrnush Parsipur article. This can't be surprising to Gwern: his methodology clearly selects for marginal links, by trawling for them in the disfavored "External Links" sections of articles far out into the long tail of interest on WP.
This article was written in 2009, and makes predictions about the future of the project. Were those predictions accurate? It doesn't look like it: article creation has grown steadily, and editor participation has been remarkably stable for years. Has the Wikipedia community moved away from its "deletionist" stance? This comment thread sure doesn't think so, and I agree. So: what gives?