I definitely think defenses have been noticeably handicapped. Some of it is obviously for safety, but not all of it. Ball carriers stiff arm to the face and lower their heads all the time. Stuff that the defense would be flagged on if they did.
Marketability dictates more rule changes than people want to admit. I'll never understand why so many people just want to watch constant scoring. I love great defense and think it's more interesting than high scoring shootout games. I'm in the minority though. The NFL knows the more casual fan just wants to see non stop touchdowns and does what they can rule wise to make that easier.
Is there an explanation for why you don't get a 10 second run off for intentional grounding as long as you also commit another penalty on the same play?
They were punished less for getting two penalties than they would have been for one.