there is ups and downs in the NFL every season, for every team. you can literally do this for every team in the nfl (with a very very few exceptions)
part of the issue was the defense, just giving up points so easily and making the offense one dimentional often.
but for example, seahawks were 3rd in scoring, but had similarly 4 games they scored less than 20 (won 2 of them because of their defense)
rams were top scoring and had two games scoring less than 20 (won one of them because of their defense)
similarly bills who were 4th in scoring had 4 games scoring less than 20.
lions had 5 games scoring less than 20, including one against those very chicago bears you mentioned above. and they won that game. because of defense.
are they above criticism? no. absolutely not. but I don't think that's the right approach, thinking they should score a ton every game. that rarely happens in the NFL (2013 Broncos and 2007 patriots for example, both of whom lost in the superbowl because they couldn't score).