They are the epitome of why wins aren't soley a quarterback stat. Those two teams are also excellent examples of why winning is a team thing, not a quarterback thing. Of course, one would ultimately prefer to have a good quarterback at the helm of a winning team due to the position's importance. But if winning was soley because of a quarterback, it would either be Brady or Rodgers winning the Super Bowl every season. Maybe Brees here and there too. As it stands, the two quarterbacks in the Super Bowl were Flacco and Kaepernick. Two solid, but not great quarterbacks. The reason they were in the Super Bowl was because the teams around them were very good.
Further, if you're going to use the fact that Tebow took what became a 13 win team the following season with Manning, guided them to the playoffs, and beat the Steelers as a reason for why he's a good quarterback, then you better be prepared to tell me why Brad Johnson and Trent Dilfer belong in the Hall of Fame. They won Super Bowls. Tebow won a wild card game.