Google To Keep Your Searches On File For TWO Years

I understand why Google wants to track searches and see how effective they are and refine their product. What I don't understand is why Google wants to keep everyone's searches grouped and traceable back to their own personal computer. What possible purpose does that serve? Google used to keep this info indefinitely; now Google says it will "only" hold onto your personal searches -- traceable right back to you -- for 18-24 months. Gee, thanks. AOL keeps searches only for 13 months, which is better but still unjustifiable in my mind. Any company that launches a good search engine that promises NEVER to keep records of my searches that can be traced back to me will immediately get my business. I use Google all the time but I don't feel the slightest bit of loyalty to it.