Absolutely!!
Catchy, I'm not the one claiming there's only one factor to winning a super bowl. The QB is the main ingredient, no doubt. However, the QB needs a D. Name a super bowl that was won w/o a good/great D performance.
Order of importance to winning a super bowl: QB, DLine, OLine. Formula is, protect your QB, get to theirs. If you can't stop the other team, your chances of winning go way down. Look what happened in Brady vs Foles. The NE D was 29th in yds allowed. And for those of you who try to claim yards don't matter, the NE D was 5th in points allowed. But, those yards allowed suddenly mattered when they couldn't stop Foles from walking up and down the field on them. Brady's 33 points were suddenly not enough. Why? BECAUSE HIS D COULDN'T STOP THE OTHER TEAM.
Think about that. It took D to win. Brady, the best QB of his era, lost. Because he had no D. Think, Catchy, think.