I quote:
The NFL said, however, that the copyright law on its games is long-standing and the language read at the end of each game is well known: "This telecast is copyrighted by the NFL for the private use of our audience. Any other use of this telecast or any pictures, descriptions, or accounts of the game without the NFL's consent is prohibited."
The league bans public exhibitions of its games on TV sets or screens larger than 55 inches because smaller sets limit the audience size. The section of federal copyright law giving the NFL protection over the content of its programming exempts sports bars, NFL spokesman Brian McCarthy said. "
In other words, exempting sports bars isn't the NFL's idea.