The problem is the hierarchy which looks the other way and may actively encourage the criminality. If Goodell and company would administer some real punishment — an astronomical fine, permanent expulsion or whatever — these shenanigans would stop.
Oh gosh. Before Hi-Def and 15 cameras for instant replay the game was a LOT dirtier. Fingers in the facemasks, punching and woe be any player driven into the opponents bench.
You must have never heard of Conrad Dobler.