Google has increasingly tailored its search service with individuals' data, but clickthrough rates can't reflect a community's desires.
Startup incubator founder Paul Graham has a great post about the "frightening" startups he thinks "could make you a billionaire." Within it, there's a pocket critique of Google's latest iterations that rings true:
[L]ately when using Google search I've found myself nostalgic for the old days, when Google was true to its own slightly aspy self. Google used to give me a page of the right answers, fast, with no clutter. Now the results seem inspired by the Scientologist principle that what's true is what's true for you. And the pages don't have the clean, sparse feel they used to. Google search results used to look like the output of a Unix utility. Now if I accidentally put the cursor in the wrong place, anything might happen.
Thinking about Google's company dynamics, I have a hypothesis about how this might have happened. It has everything to do with the limitations of data-driven design. Let me stress that this is just a guess.
So, Google collects data on user behavior. They make changes to the user interface and collect more data, analyzing what they've got to see what users "liked" more. All these little tweaks and personalizations and speed enhancements got incorporated on the basis of THE DATA. And who could argue with that? Give the users what they want!