To the left is an analysis of a thirty-minute broadcast cycle on CNN Headline News. As you can see, you get about six minutes of actual news. What you get instead would be most charitably described as "soft news" or "human interest" stuff -- and commercials, either for products or for the channel itself. The author of the analysis does not like sports, and I would agree that sports is not "news" even though I enjoy sports.
And ten minutes of commercials in a half-hour broadcast that costs next to nothing to air. The stories themselves are clips from regular CNN segments, condensed in the editing room with faster edits. CNN may spend a few million dollars a year on editors, crew, newsreaders, and sales for Headline News, but I'll bet that after about twenty days of broadcast a year, it's pure profit from there on out. Not that profit is a bad thing, but it makes you understand why the content is what it is -- it attracts eyeballs, which is what counts to the sales department. Hard news content is harder to sell than Kylie Minogue returning to her concert tour, shaking her ass for the camera.
I suppose I should bear in mind that journalists work hard on even those kinds of stories and they get their assignments from editors. I'm sure that they all want to do things like cover the Senate and foreign relations and do serious news. (Well, a lot of them do, anyway.) They hope to graduate from this stuff to "real" news. Few will, unfortunately. There is only so much political activity, only so many natural disasters, to cover. And there's a lot more air time than that to fill. So, here, go get some film of the water-skiing squirrel!
I didn't find a similar graph for Fox News' equivalent of CNN Headline News, which also purports to give the viewer a complete news cycle in thirty minutes. But I would expect that Fox would be at least as heavy on the sports and celebrity reporting as CNN. One thing to say in defense of both Fox and CNN, though, is that a broadcast schedule like this means that at least 80% of their broadcasts are free from any discernable political slant.