I think it's fairly obvious that the NFL will be joping Carolina & San Diego lose this weekend.
If Denver wins, then the AFC Title game will be a dramatic Peytong vs Brady or Peyton vs Luck. They'd probably get higher ratings with Brady but both would be great stories all week. Although San Diego brings a good story with them, the NFL does not care about the diehard football fan, they're going to watch no matter what, they want the fair weather fan & you get those by having teams they recognize in the game.
In the NFC, if San Francisco wins, then the NFC Title game is either San Fran vs Seattle Part 3 or San Fran vs New Orleans. Carolina would not pull in the fair weather fans at all. I'm not certain which of the above situations would bring in more fans, Seattle or New Orleans. Probably the Saints.
I'm guessing the NFL wants San Francisco in the Super Bowl from the NFC, they're probably hoping for either Denver or New England, both would draw from the AFC.