You think it started with this? US media didn't even want to report on the issues with Obama, rather all they wanted to do was sing about his racial background without doing any digging. Media in the US has long since moved from "providing information and letting you make a choice" to "telling you their point of view, framed as news." This is why Journolist existed.
As for cultural attention span being exhausted? Hah no. Rather the media is doing it's best to try and change the viewpoint on anything that happens especially when it becomes too "hot in the kitchen."