This point is well made and certainly relevant, but...
Unfortunately, in the research being done on the concussions, one of the issues is that when linemen meet at the snap of the ball, the G forces on the head when the big boys clash are very high. It's believed that the hundreds of contacts that happen like this are part of if not the major cause of the problem. I don't know how you would be able to change this aspect of the game while maintaining the core essence of football as I don't believe you could change or referee technique to avoid this clash of heads.
You're spot on and you can't stop this. Even in Rugby, without equipment, there are issues with concussions. The reason they are slightly more under control is the rules enforced in the sport.
Equipment is needed, even if it does make players feel more invincible than they should feel. Even if you manage to get players tackling properly and cleanly, there is still going to be the issue of the linemen and the forces they put themselves through and there will still be concussions on would be tacklers and ball carriers. It's the nature of the sport and the player does have to take some responsibility when it comes to playing it. As I mentioned, I was hit cleanly and got hurt badly...it happens...it's the way of the sport. Whilst I welcome the rule changes, I accepted that I could get hurt badly when I started playing and when it happened I picked my head up and moved on.
In essence, I like what the NFL is doing. They are aiming on restricting where you can hit and hope that the coaching filters through...which it should have done anyway. I don't know any coach that doesn't teach how to hit and wrap properly so you need to clamp down on players who hit the wrong way with these rules and force them to do it the right way.
The aim is that by clamping down, they force players to tackle the way we've always wanted them too. NO coach ever wants to see a player hitting above the wast line anyway.
Perhaps those of you here who are familiar with rugby rules can address this...
Many people here (and elsewhere) take the "be like rugby -- ditch the helmets, etc.".
I've read a response to this that makes a lot of sense if the underlying assumption is true. But I don't know if it is true, hence the question.
The counter is along the lines of:
"It still wouldn't work. In rugby it's getting the ballcarrier down that matters, not such much how many yards he may drag the tackler before he goes down. So in rugby there's no need to go for the 'stop the guy dead in his tracks' shot. By contrast, in football yards matter immensely and so there is great incentive to deliver a 'stop the guy dead in his tracks' shot. If you took away helmets, either defenders would injure themselves more trying to deliver such shots or you'd have to change the rules of football to make yardage not matter as much."
Like I said, I don't know enough about rugby to know if the yards-don't-really-matter-much thing is true or not.
In theory, the lower you get, the more leverage you have and American Football is all about leverage and getting lower than the guy opposite you.
Yardage is not statistically measured in rugby, but when it comes to goal line defense, it's as important to make sure you stop a guy dead in his tracks as in any sport of its type.
I've always said the way rugby players tackle is more efficient than that of American football. Having lived in the north of England where Rugby League is a way of life, I got to watch a lot of it and I have always said the NFL should emulate it.
I rarely ever see a rugby player with the ball falling forward...EVER. Therefore for me that just enforces exactly what I have always thought...rugby players are better tackler than American footballers.
I played for 5 years and the best tackler I ever saw over here was a guy who played rugby. He aimed for the waist, wrapped up, grabbed jersey and churned his feet harder than anyone I ever saw...got his arm under the guys leg and lifted it from under him to help if need be. That's how you tackle and IMO it's more effective in preventing yardage than any form of high force shoulder hits NFL players like to do...it's more successful and much more efficient.
At worst, if you do it the right way, you stop him with forward progress or you hold him up in time for your team mates to help you...
I think the biggest difference is that the passing game in football puts more players out in open space where collisions come from different angles of pursuit.
I would say there's a tiny bit of difference, but the same theory and technique is applied in rugby. If you're coming from an angle, you do a similar thing. Just make sure you take the right angle, get your head in front of his body and use the opposite shoulder to the side of the field you are chasing. Wrap up and secure the ball carrier and keep your feet moving.