This year’s television upfront presentations, where the networks open giant briefcases and introduce samples from their fall lineups to advertisers, came and went with whimpers. But the entrance whimper and the exit whimper were different. The first, at NBC’s presentation Monday, was one of pain. It came through on the projection screen behind Kevin Reilly, the network’s entertainment president. “Big fat disappointment,” the screen read, the acknowledgment saving Mr. Reilly from prolonged public penance by subtitling his subconscious. It had indeed been a horrible year for NBC, which, having long ago lost its first-place status, needed a brilliant one. How the mighty have fallen. And how the unmighty have risen: Fox, which after all these years is still not counted among the “big three” networks by some old-timers, now attracts the audiences advertisers desire more.