I totally see your point, but I think more importantly the question is less "Why isn't O'reilly Web 2.0", and more "Is Web 2.0 over yet".
Many of the examples cited in this article from 2005 are now just spam or corporate controlled BS.
"Search Engine Optimization" - Spam
"Napster" - Corporate controlled DRM
"Blogging" - Supposedly over 90% of the blogs are abandoned, most of the rest are corporate sponsored now
"Participation" - I'm not sure what this even means, but things like Lulu are just a slight retooling of a very old vanity publishing industry. There has been an increase in independent music publishing, at least.
"Syndication" - I assume this is stuff like Twitter? Which has no user retention, as something like 90% of people use it for a month or less?
My point is just that while I think that the AJAX/JS heavy web app styles and the Service Oriented stuff has certainly gained some traction, the user created content and democracy aspects are pretty much dead. This and Social Media seem to be winding down as movements, while some of the ideas behind them have moved on to bigger and better things.
At what point will we declare the end of Web 2.0 and the beginning of Web 3.0?