I know that this penalty is difficult to call, but I think it's necessary.
There's a rash of concussions in football. I don't think it is happening because of player's using certain techniques. It's almost all due to simple physics. I used to lead with my head in both blocking and tackling; that's how I was taught. Further, the only concern in those days was neck injuries. How come?
I played in college (Div 3) and high school at 5'10", 200 lbs. I played both OL and DL at that weight and was about the usual size. The biggest guys on all the teams I played on were the same size: 6'3", 220lbs. Iow, about the same size as most RBs today. Linemen are typically in the 6'2" - 6'5", 260 -320 lb. range and they are trained up to be both stronger and faster. No wonder more people are getting their heads knocked off.
Well, we can't stop young men from growing and there are limits to equipment improvements. Result = new penalties aimed at trying to reduce head to head contact. It's either that or parents will increasingly withdraw their sons from football, as is now the trend. The sport will not die from this, but it'll get replaced by soccer if this continues. It'll become like football in Japan (They play football in Japan!? Yes.), a minor college sport, sort of like wrestling.
That may happen anyway, but if targeting penalties can reduce the injuries that endanger both the players and the sport, then we need to keep them.