The CTE revelations are pretty recent. Considering that virtually all players college and above who have since passed away and were tested had developed this should cause alarm for anyone.
Fixed for accuracy.
It was noted in more than one article when that story came out a month or two ago that it is only some fraction of all players that were checked. And it's extremely probable that people who had a reason to suspect some sort of brain issue (behavioral changes observed, etc.) would be much more likely to have a person tested than those who didn't have any reason to suspect something was wrong.
That's not to minimize the issue. But you original statement was sensationalized.