I'm fine with holding penalties for the most part. Most of the time they are called when there is an advantage at the point of attack, a guy gets beat, or the QB breaks the pocket and a linemen doesn't let go. It's stupid when they start calling them away from the play unless they're egregious. I didn't see every hold called on the Hawks to comment, but you have to play really poorly to have every first down conversion called back on a hold for an entire quarter. Not only that, but if you're playing that poorly upfront, there would be multiple holds on 1st, 2nd down as well. I think it's really easy for refs to zero in on a backup struggling and almost get tunnel vision. At that point you almost need something else crazy to happen to reset the refs focus and get him off the guy's jock
Now, PI is a joke in football anymore. There are a number of PI calls every week on the Defense when the receiver clearly pushes off and the defender has done absolutely nothing. The way they call penalties on defenses makes the game hard to take seriously anymore.