1) Many people don't realize that tracking isn't just about having something to hide. But, it can cost you money. From Airline tickets to staplers you pay based on a profile:
http://www.wsj.com/articles/SB100014241278873237772045781893...
http://www.wsj.com/articles/why-you-cant-trust-youre-getting...
2) People don't realize what's being tracked. I usually send them to http://history.google.com/history to have a look. Or http://webkay.robinlinus.com/ to see what their browser can access. That makes a lot of people realize just what is out there.
3) People feel they can't search without personalized searches.
The example is often a matter of disambiguation. For example, if I type "Python" I want code, not snakes. But, really, when is the last time you only typed 'Python' and wanted something generic about Python? You probably wanted a package lookup or the latest news on a release. So if you become more specific there is no issue.
Plus when you get a bit more specific on Python you can trigger things like package lookup:
https://duckduckgo.com/?q=python+numpy&ia=about
Or NumPy Cheatsheet:
https://duckduckgo.com/?q=numpy+cheat+sheet&ia=cheatsheet
At the end of the day some people may truly be ok with all the tracking that takes place, and that's ok that's up to them. But, at DuckDuckGo our goal is to educate people on online privacy, and provide a trusted way to access information as best we can. (Not to mention Instant Answers and Bangs which are super addicting)