I understand the attack on football given that is where the brain injury data started (and rightly so), but data proves girls soccer is equally as dangerous, and now the winter sports are attracting attention as there are only a handful of helmet laws for skiing, snowboarding etc. In addition to the incidence of concussions in sports, the country has very inconsistent helmet laws for motorcyclists which means the conversation is much larger than football.
This part of the conversation is a bit off topic, but if we want to solve the brain injury issue, we have much work to do in many areas and that creeps into our freedom of choice.
http://www.iihs.org/iihs/topics/laws/helmetuse/mapmotorcyclehelmets
https://www.denverpost.com/2016/12/24/concussion-awareness-winter-action-sports/