Many charts and maps have headlines, and sometimes they are misleading. Perhaps this is because sometimes graphics artists are writing them without seeing the stories they accompany.
Perhaps that's the case here. This graphic goes with a New York Times story about how some radio stations are experimenting with video. (Think Howard Stern on E! back in the day and Don Imus on MSNBC.)
Despite the headline on the graphic, the story doesn't indicate that radio listenership is down because people have shorter attention spans nowadays. It's entirely possible that attention is simply being paid elsewhere. Headlines on graphics shoudn't come to conclusions that are not backed up with facts within the stories they are paired with.
It's up the copy desk to reconcile those contradictions.