So what are we saying, Nick Foles discovered talent for the playoffs then it disappeared? All this talk about how football has changed dramatically is way overblown. The only thing that changed is the proclivity of the refs to throw little yellow flags. The ability to throw accurately hasn't changed. QB's today aren't better or more accurate than Dan Marino. He would put up astronomical stats today.
Eli Manning will make the HOF for one simple reason... two Super Bowl rings. Not because he was a dominant passer. Terry Bradshaw was nowhere near the best passer of his generation, he has four rings and is in the HOF. Wins are a "team" stat, no QB no matter how good can will a bad team to a Super Bowl... if so, provide a single example. I can provide numerous "average/good" QB's who won Super Bowls... nobody can provide a single example of an "average/good" team winning a Super Bowl.
If Nick Foles, Eli Manning, Joe Flacco, Brad Johnson, Trent Dilfer and others can do it... if Joe Gibbs can win three different Super Bowls with three different average journeyman QB's... then you don't need some magical mystical QB.
Kapernick, Rex Grossman, Jake Delhomme, Matt Hasselback, Rich Gannon all made it to the Super Bowl in the last 17 years
You need good QB play, the same way you need good OL, D and Special Teams... it's TEAM.