The offense can't keep making up for the deficiencies of the defense forever. The defense has to step up sooner or later and stop teams when it counts. They haven't done that.
Well that's exactly what we gave Drew Brees the highest paid contract in NFL history to do, and he's not living up to his end of the deal. He held out, we lost potential signings over it, and now he's playing like shit. Don't get me wrong, I'll always love the guy, but he's lost some of my respect, and I've come to the realization that he's nowhere near the best QB in the NFL like I've thought since 2009.
Mike McCarthy developed Aaron Rodgers into the QB he is today, but if McCarthy had to leave for a year, I doubt Rodgers would then start playing like trash. Same for Brady.
Sean Payton made Drew Brees into the QB he is and now Brees can't function without him. It's as simple as that. Without Brees playing well, an already hurting defense gets put in horrible situations. Look at Indy last year... without Peyton Manning there, all of the sudden it's not just the offense that is worst than ever, but the defense as well. Coincidence? No, great offensive play severely helps the defense out. And when a franchise built on their offense all of the sudden can't put numbers on the scoreboard or win the time of possession battle, then the defense will not play well, period.