In the media there are a few powerful forces at work:
1) Ratings/Sales
2) Careerism - (Nobody is remembered for breaking that incredibly happy story.)
3) A filter that streamlines news to fit 1 and 2.
Ergo, your nightly news is pre-chewed so there is little ambiguity or complexity to digest, and iconic. Just think, what are the images of the Iraq war that the media has broadcast and rebroadcast- I can think of a few - the statue toppling, the bagged head guy at Abu Garaib, Jessica Lynch, that armless and legless little boy, etc. You can be familiar with all these iconic images and know sh-- about what is happening there.