There are still people that visit those outdated sites and many are coming from search engines like Google. Despite Google's efforts to have a comprehensive index, there's a growing subset of the Web it can't properly index and that's Facebook. Sure, Google indexes a lot of Facebook pages, but that's like trying to find your keys in a dark room. Google needs Facebook's map to index all the pages and find the connections between pages and between users, but Facebook is not willing to license this valuable data to the most important competitor. Google tried to make the web social and failed, so now the only option to stay relevant is to build an alternative to Facebook's walled garden and that's Google+.
+1s are the new links, authors have profiles, companies have social pages and this new universe will try to coexist with the old Web in Google's search results. Google tried to focus on the users and find ways to make the social Web more open, but now it has to focus on itself and do everything it can to stay alive and maybe even save the Web. "Google's mission is to organize the world's information and make it universally accessible and useful," but that's impossible if it can't access, understand and rank that information.
Back in 1996, Larry Page and Sergey Brin used links to determine the importance of a Web page. Now links and pages are no longer that important and the old rule of trying to send people to other sites as quickly as possible is difficult to apply. Showing personalized results requires understanding users better, encouraging them to share more content and create connections. In many ways, Google+ is the anti-Google and that's why it's difficult to understand some of the new features.