Does everyone know that slamming your head into a 300 lb. hunk of linebacker is probably not good? Sure. But if the organizing league had information that the problem is much worse than reported, and refused to take action to fix the problem, all in order to make a profit at expense of the players’ health, that is a problem too.
When I was growing up, my grandfather was a smoker. As entertainment for the grandkids when we’d go to visit, grandpa Harris would stand up on a chair, hold his lit cigarette up to the smoke detector, and set off the alarm. Now that’s fun.