A broadcast network is still the best place for a television event to get notice. That holds no sway with Emmy voters, though. It’s not new that the Emmys’ attention span has wandered. Still, the snubs offered to broadcast leading lights “Empire,” ”The Big Bang Theory” and “The Good Wife” in Thursday’s nominations were notable. The music industry drama “Empire” was one of TV’s biggest hits upon its January debut, almost single-handedly keeping Fox afloat. That wasn’t enough to earn a best drama nomination, and lead actor Terrence Howard was also overlooked.