I don't disagree that hitting [vs checking] is something that's become a problem, especially due to the factors you cited, like the speed of the game increasing, armor on the players, and the mental shift to encouraging the light's out approach. I personally despise the open ice hits that the likes of Stevens and Kronwall deliver. It's simply unnecessary in accomplishing a defensive play, which is ostensibly the reason for the hit.
With that said, hitting certainly does result in concussions, and the players I mentioned above were all the victims of these deliberate intents to knock someone into the next century, and until recently were probably considered legal hits for the most part. When I use the term 'checking' I really do mean the old school check. The hip check is actually one of my favorites, an almost disappearing art unfortunately, but rarely something that will injure an opponent, for example. It also never resulted in a player getting jumped for delivering a clean/legal check, so there's a lot of merit to the respect for each other and the game argument--- but let's not lose sight of who it is that encourages and demands that players 'finish their checks' too.
