The Broncos did not have a good QB or passing game this year.
According to FO.com, the Patriots ranked 4th in passing efficiency, the Cardinals ranked 3rd and the Panthers ranked 9th.
In the prior season, the Patriots ranked 5th, Seattle ranked 10th, Green Bay ranked 2nd and Baltimore ranked 6th.
The year before that, Seattle ranked 8th, Denver ranked 1st, New England ranked 6th and SF ranked 4th.
In 2012 it was Baltimore ranking 15th, the Niners ranking 5th, New England ranking 1st and the Falcons ranking 10th.
In 2011, the Giants ranked 4th, the Patriots ranked 2nd, the Niners ranked 14th and the Ravens ranked 13th.
That's the last 20 teams to make it to the NFC Championship game and only the Broncos finished outside the top half in Passing Efficiency. And that was with Peyton injured and when he came back, he passed more efficiently than he did before he got injured (and more efficiently than Osweiler).
Out of those 20 teams, only 4 of them finished outside the top-10 in passing efficiency. And the team that continually ranks high in passing efficiency each year is a team that continually makes the playoffs in the Patriots.
The Broncos were more the exception to the rule. A great defense keeps a team in games, but it's not likely to win too many games outright.
Obviously, the Cowboys need to get much better on defense, but it would be a mistake to pass up on a good, young QB in the draft because this is such a passing oriented game.
YR