It seems sort of like you're destroying the possibility for growth with this, though. From what I understand of Google's work, they really have improved tremendously from analyzing data (to find how searches go wrong), and from using the data in new features (such as with spell checking, adding new terms into the query, personalizing searches, etc.).
And I mean, I value privacy. I do. But, I value the quality of the search results even more than whatever privacy is lost from search engines logging, I guess. Unless there is some path to improvement, all I can ever see myself using Duck Duck Go for is porn, tips on murdering my spouses, and information on illegal drugs. Of course, other people would use it for much more-- but for me, there something truly wonderful about being able to search for "nose" and have the first result be a unit test runner I want to use, not a piece of anatomy I already know everything I need to about. Sure, it's stupid-- I should search for "nose tests", but I sometimes make mistakes, and here Google doesn't even need to say so and make me try again. It finds the target anyway, without problems (and the less-likely Wikipedia article is right below, as result #2). Without Google logging what I searched for and building a profile, this wouldn't be possible.
I don't mean to be fanboyish and loving of Google (they do scare me sometimes). If they added some sort of feature that said, "don't record anything I do right now with these searches", I would be very happy. But, similarly, I would also be happy if Duck Duck Go at least had an option to opt-in to logging and monitoring and so on. On my end, I would consider my relatively minimal, and explicitly given, loss of privacy to be worth it to help make a search engine I am using better (assuming, of course, that I'm using it-- and I'm not opposed to trying something new to me).