on Flickr: a conversation in the comments section of a photo brings up all sorts of issues.
Another downside of ahierarchical, network-based, user-centered design: not all users are created equal. Take out the center, and not everyone can immediately adapt to figure out how to get around. Grand Entrances, Urban Monuments, Help Desks, and FAQs might have unpleasant associations with authority, power, and control, but at least they give the uninformed user a place to start. Why should the onus be on the user to figure out how to check out a book, or use your website, doesn't this just privilege some users over others? And from the designer's end, as synecdoche points out here, what's the difference between deliberately leaving a structure open-ended, and just plain not giving a crap?
In urbanism, the classically Lefebvrian response to the generic is to repurpose, rewrite, reinterpret, or reappropriate. But when you're just trying to get through the day, who has the time for that kind of thing? In short, the privileged: the overeducated, underemployed aesthete with too much to think about, and too little to do (pot, meet kettle).