I gotta be honest, I'm fine with the rule itself. We should probably revisit this once we see how it is officiated, instant replay delay of this, impact on the outcome of games it has, etc. But headhunting does happen in the NFL.
We need to incentivize NOT-headhunting, and this seems like a reasonable attempt to do that. But it is trial and error, so we should keep tweaking it until we get it right. Otherwise, concussions and the non-fan impact that they rile up, are likely to have a very negative impact on the NFL, and possibly even the existence of football as a game for both the NFL and colleges. I can take an NFL without helmet-to-helmet contact. I can take a few bad ejections and a few changed games. But I really want to avoid the loss of football as a sport. Once we fall a certain way down that hole, there is no returning. So, find a way to deal with the problem. It will be healthier for the players, equal to the teams, and help the sport thrive. If this rule isn't the right one, we should change it. But, it seems worth a try to me.