I hear ya.
And I will use DuckDuckGo more now.
The idea is that the aggregated data can be used to profile you, where you go, who you meet, what you like and dislike and more.
This could be in terms of political party affiliation, food preferences, and protected info like sexual orientation. Data aggregators can be used by potential employers, and false ideas gleamed about you.
I personally am very private, and do nothing that should concern others, etc (nothing bad), but I like the idea of knowing whats going on.