The goalposts are being moved in here, and the argument keeps changing with every post. It starts with a QB not being worth that high pick, then it turns into "Oh, only elite QB's are worth more than defensive players".
2016: Brady
2015: Broncos defense
2014: Brady
2013: Wilson/Seahawks defense
2012: Flacco
2011: E. Manning
2010: Rodgers
2009: Brees
2008: Big Ben
2007: E. Manning/defense
2006: P. Manning
2005: Big Ben
The majority of that list of Super Bowl winning QB's since 2005 are upper echelon QB's.
Let's take it a step further and go with the final four QB's during the past few years;
2016: Brady, Rodgers, Ryan, Precott
2015: Brady, Newton, Palmer, Brock/Manning
2014: Brady, Luck, Wilson, Rodgers
2013: Brady, P. Manning, Kap, Wilson
2012: Flacco, Brady, Kap, Ryan
The majority of the QB's that remained were either elite or more than average during those seasons. The QB position is without a doubt the most important position.