I agree with you - clearly the OP is an example of a kid whose trainer is prioritizing a look. And I certainly don’t disagree that “a bunch of hair” shoved under a helmet compromises its intended function.
People are using safety equipment improperly. No argument. But, again, what I want to know is the scope of it – and does it require a rule to solve? For instance, these days I’m not seeing a whole lot of juniors wearing their harnesses hanging a mile below their chins. Which used to be a thing IIRC. The rulebook still simply says “properly fastened.” Over the years, I’ve known kids and adults to purchase items - including helmets - that were too tight or too loose because the price was right or the brand coveted. I’ve also spent enough years in backyard barns and 4H – where, believe it or not, hardly anyone, if anyone, does “hunter hair.” I can tell you I wouldn’t guarantee everyone’s helmets are all fitting right. You see them shifting forward. You see them shifted back.
Perhaps even, the rule isn’t hair, it’s simple fit. I still don’t know how you demonstrate that without checking heads - unless the problem is obvious (10 miles of visible forehead or a brim on the nose?). Photos only provide a guess at fit.
To that end, I also understand that helmets are designed to fit closely to the head. However one person’s thick hair down may equal my thin hair up. Which is where I have questions and am eager to do additional reading. I am familiar with Mary Babick’s original article and I remember it citing research but not necessarily with specificity (I am a COTH subscriber and will be going back to the archives). Similarly I have read Dr. Chambless’s work referenced, but don’t recall much about the quantifiable scope of this problem. If anyone can point me to where I can read more of that (papers on the topic, research), I’d be appreciative.
But I also have to ask what the logistics of enforcement looks like. We spend a lot of time trading tips about doing hair neatly and discreetly. These threads are full of people demonstrating their alternatives to hunter hair where you “can’t really tell” unless you’re right up close. Given the depth and breadth of people’s hair and not everyone has Dani Waldman locks or feathers visible from space, this opens up a lot of administrative questions. Hair down isn’t always going to be as obvious as an errant martingale in the hack.