The defense has improved. It is still average-to-below-average in the middle of the field.
The offense? Injuries, sminjuries. This offense was nowhere near as good as people think it was before the injuries. McCarthy hasn't been the "offensive innovator" for years. Rodgers playing at an all-world level covered up shortcomings of the OL, the WR, the TE, and the coaching. The fresh body of Eddie Lacy covered up other shortcomings of the OL and the TE.
Now we have Rodgers coming down to earth (and below). Now we have Lacy, like the last great Packer-power-back-behind-a-weak-line, John Brockington, showing the cumulative effect of the pounding he took in earlier years, and on top of it adding weight.
And the offense is shown to be what it is. A team that can't do what it takes to win at home against any division team.
Go ahead and think that a healthy Jordy Nelson and a healthy Baktiari and a healthy Bulaga would have made the difference.
An all-world offense and this defense would probably have been good enough. But this is not an all-world offense. It hasn't been for years.
And do not be conformed to this world, but be transformed by the renewing of your mind, that you may prove what is that good and acceptable and perfect will of God.
Romans 12:2 (NKJV)