First of all, for some reason it's headline material that Anthony Barr wasn't fined for the hit that injured Aaron Rodgers. It was a legal hit, so that headline is essentially Water is Wet.
Anyway, since that injury I've been thinking about whether or not that hit should be illegal. First and foremost, I too would be upset if my quarterback got injured on that hit, but there are a couple of other factors that need to be considered, and once they're considered, the answer as to whether or not that hit should be illegal is a definitive NO.
1. Mobile QBs would essentially be allowed to a free pass on their first defender outside of the pocket. If that hit becomes illegal, defensive players would be forced to let up, resulting in guys like Cam, Rodgers, Wilson, Wentz, etc. having an easy way by said defender if they decide to run.
2. Rodgers broke his collarbone because he braced himself. Had he not braced his fall, nothing would have happened. Barr didn't actively drive him into the ground. He landed on him, but that's kind of what happens when you tackle someone. The hit had almost nothing to do with the injury because quarterbacks take hits. It was a fairly normal hit.
Anyway, I just think it's bad for the game if the league decides to make this hit illegal. What do the rest of you say?