It's a deeply ingrained cultural tradition in a lot of places. It's an extremely hard sell to tell people to reject their traditions because of a relatively nebulous and uncertain danger. "I played football and I was fine" is a powerful argument.

Still doesn’t mean you can’t look at those people as foolish, no different than if they handed a cigarette to their teen or let their kid get obese.

CTE is not nebulous and uncertain. If it were not for "tradition", it would be considered child abuse to let them repeatedly slam their brains into their skulls.