there's big MONEY to be gained but suing the NFL/colleges/HS etc for CTE so there's motive..
A few years ago I was part of a head injury research study at a local VA hospital,that study being "supervised" by Harvard Medical School.In BCT (many,*many* years ago) I sustained a head injury.Given that injury I was deemed a fitting candidate for the study.I had an MRI and CT scan of my head,lots of blood was taken from me, I had a number of tests of my memory and a physician asked me many,many questions about the incident and my life since the event.
It's easy to see why the Armed Forces would want to study head trauma just as it's easy to see why the NFL,the NHL and professional boxing would.Head trauma can be the result of falling off a bike,being in a car accident,playing football or hockey...or just falling down the stairs.
It's stupid to make the medical study of head injuries a political issue...just as surely as it is to make foot injuries a political issue.