If they had been playing tight coverage and Marshall caught a deep ball and scored at TD everyone would be pointing to the Atlanta game and ripping him for letting a receiver get deep.
The difference is Atl had under a minute and started at the 1. Chicago had over 2 minutes and started at the 22. Chicago had time to dink and dunk their way down into FG range and that's what we should have defended. Atl's only real chance was hitting a long bomb, so that's what we should have defended. Both situations were handled the opposite of how they should have been.