It's kinda depressing that this article is basically just a copy of one I wrote in 2010 and it's still something that gets attention as interesting stuff. Nginx documentation obviously still has a long way to go.
I instantly thought of your article when I saw this one. I also defended NginX's documentation and linked to the actual documentation, which I think most people forget exists over at http://nginx.org/en/docs/ .
The official nginx documentation is better but it's still mostly just an API documentation, there's no red thread through it to tell people "read this first, then this and then jump over here".
Since this kind of article still gathers this amount of popularity 3 years later I actually do think it's a problem of the documentation.