Yes, this is the thing. Defensive players have to be coached and learn to avoid helmet contact at all costs. It protects them from concussion as well. The worst thing that happens is missed tackles and more scoring on offense which is more popular to fans in general anyway.It does not matter. They are trying to change habits and behaviors on the field, whether intentional or not. Defensive players have to stop lowering their head and leading with their helmets. It’s Dangerous for them and the players they are hitting. The only way to do that is to kick them out of games.