No. NFL ratings were never based on seeing violent hits. It was based upon watching competent play.
I think the expanding NFL culture of trying to get away with cheating on every play is hurting the game. Not only do the antics of Brady hurt the game, but the perception of HGH usage (and the increase in injuries and churning of rosters) as well as just the idea of OLs and DBs trying new ways to hold and not get caught on every play makes it less entertaining to watch than before, IMO.
It would be like watching a NASCAR race where you knew that every car didn't meet specs in some way, but who won the race would depend upon which official caught which driver cheating. The game wouldn't be about building and driving the best car, it would be about who could get away with what. Maybe in some circles, who can get away what might be interesting, but for most people, its not something they relate to, hence the decline in ratings.