The way I’ve always explained the intrusion of these sorts of stories or the overkill on a single breaking news story is to compare cable news networks to a local restaurant (See here for example).We like the local watering hole the way it is. We like to order “the usual.” We want inside dish and the like.
But the owner of the local joint desperately wants more customers, so he’s constantly trying to woo the giant busses, full of tourists, to swing by. The tourists basically want their one pre-paid, pre-packaged meal and then they want back on the bus. For the regulars, it ruins the joint, the atmosphere, the food, the service etc. But the tourists and the barkeep just don’t care.
Something similar happens with network cable news, as Tim notes. The ratings from the regulars aren’t very high. Most people don’t watch any of the political shows we all yammer about. So when a famous person dies or there’s a murder mystery, these networks hang-out the “tour busses welcome” chalkboard bill-of-fare as quickly and as long as possible.