You're conflating two different issues. Offensive play calling and defensive performance.
The offense was fine. We had such a "poor" showing in the second half because we didn't have the ball. In three quarters of play, the Packers scored on every drive they had the ball, except for the end of the first half where they ran out of time. 4 drives. 2 successes, 2 failures. We punted twice, TWICE, the whole game. How much more can you ask from your offense?
The defense, particularly the secondary, played poorly. If they get just ONE stop, this is two score game and not close. If they can just force the two scoring drives to take 60 more seconds each, the games ends without us needing to run out the clock.
Now why exactly the defense had a rough second half, I don't know. I'm inclined to blame Randall the most, but without a second watching, that might be premature. See what I think I saw with Hyde above.