See, that's where we differ.
Personally, I don't miss the football of the 70's and 80's, not because I wasn't alive to witness them, but because the quality of life those men "enjoy" today and how they have to watch their buddies die and suffer from horrible diseases like dimensia, alzheimers, ALS, and the like. The steps the league has taken over the past decade, especially with the advent of concussion protocols and the like have done more good for the players than anything in the league's history, and that should be applauded.
Having said that, what Kendricks did was not only legal and not a penalty, but it is how the game should be taught! He faces up his man, hits him in the chest, blocks downfield for his receiver which is a lost fricking art, and finishes his block THROUGH the man's chest, which is football 101. The fact that a penalty was called, subsequently not picked up, could not be challenged (which I HATE), and then the offending player was fined for it is the tragedy, not the spirit of the rules.
The spirit of the rules is adding years and quality of life to men who, not ten years prior, were shooting themselves in the chest with a shotgun to preserve their brains for science (Seau).
The enforcement of the rules is deplorable.