In their own way, each of these tries to cut through the particulars of the immediate news cycle to get at a story's lasting meaning. As Washington Monthly editor Charles Peters often notes, it's a lot easier to do a story about Senator X and Senator Y jousting with each other over a mine-safety bill than it is to do one on mine safety. For the former, all you have to do is watch from the gallery and make some phone calls. For the latter, you have to get in or at least near a mine. Similarly, it doesn't take as much skill to write an interesting story about the Senate's conflict over a nomination for, say, secretary of defense as it does to write an interesting story about how the Pentagon is working under the guy once he's had the job awhile.
Conflict is inherently dramatic.
The Pentagon is not. So the bias is understandable, but not without cost. Journalism's fixation on personalities over process gives us, for example, too much information on politics and not enough on government, and too much on corporate moves and not enough on product and service performance. A textbook example is the merger story, a staple front-section business article. The thoughts and feelings of the CEOs toward the move and each other get most of the attention.