It's widely claimed (and IMO, correctly pointed out) that Fox News lacks journalistic integrity and is highly partisan, sometimes resorting to outright falsities to further an agenda.
Generally speaking, we prefer our news sources to be more objective, or if subjective, make their subjectivity more honest (i.e., by not painting it as an objective news program).
Fox News sensationalizes news for the sake of the story. This boosts ratings because it seems we are wired with a proclivity for stories, but when storytelling and ratings are your goals, something else has to give -- in this case, it's often objectivity.