What helmet proponents, even libertarian ones like Rekmeyata don't get is that there's a fundamental asymmetry here.

Nobody seriously tries to talk folks out of wearing helmets, or in any way confronts them on the issue. But those of us who don't feel helmets are warranted (for any reason) are constantly barraged by folks who think they're well meaning, or better informed, or concerned for our welfare, or whatever their motives are.

Helmet proponents also use weak data to justify their decision --- which is their right and which they don't have to justify to anyone --- but that doesn't make the data compelling. Unfortunately, well meaning folks in state legislators look at the same data, and the pattern of hemet use among the so-called informed cyclists, and may use that to pass legislation forcing the rest of us to join in.

That risk, the risk of a mandate, is the reason, and the only valid reason for non-helmet wearers to be vocal, and show the issue for what it is --- a marginal reduction in what is already a very low risk.