It was ruled that on the field, but it really wasn't that bad of a hit.
I've seen more devastating hits on the QB go unpunished this year.
Really though, there wasn't even helmet-to-helmet contact or anything. Ponder got blown up in his own endzone against Dallas, fumbled the ball for a TD and there was no flag on the play. It was a helmet-to-helmet hit and refs didn't call it.
Basically, this is football, they wear protective gear and that should be enough. It is in high school and college, but in the NFL it's all about protecting the owners' 100 million dollar investments.