Occasionally i'll be searching news stories or just the web in general, and in addition to wanting to find specific information, I find it's often helpful to read other related pages, or just generally see what else a google/bbc/whatever search turns up. If this information is filtered to my tastes, then I might start to misunderstand the 'lay of the land', or the 'big picture', or some other kind of phrase that can be put into speech marks.
I'd rather have news sources that are completely unbiased, and rely on good journalism to draw in readers (such as myself) rather than personalised news that skews my worldview.