You can think that, but you'd be wrong. They had an overall defense ranked 67th last year. That ranked ahead of teams such as Nebraska, Ohio State, Texas, Oklahoma State, Northwestern, and Texas Tech to name a few.
Their past five games last year were against good teams with Michigan State, Northwestern, Wisconsin, Michigan, and Penn State. You can't argue that this is a tough schedule. They were blown out by Michigan, but in the other four games they gave up an average of 20 points a game. That's nothing to scoff at. Could Iowa score 40+ tomorrow? Sure, but it's hilarious to assume it will be easy when you look at Rutgers recent games.
One more thing, Iowa played Northwestern, Wisconsin, and PSU last year like Rutgers did. Iowa gave up 72 points to those teams, or 24 points a game. Rutgers gave up 69 or 23 a game. So if Rutgers defense isn't solid...what is Iowa's?