If someone wants to wear one themselves the only reason they need is "I just want to wear this". That is an eminently good and sensible reason to wear a helmet, especially if they have the good grace to admit there's a degree of rationalisation in there.
Reading that I thought he was supporting pro-helmet arguments about how they protect and the evidence of any downsides can be conveniently ignored
Eh?
You managed to get a very weird spin on it if that was the case!
He is (by my reading) describing typical reactions of folk like the father of the lad in the coma, and contrasting that to the issues that need to be considered (aka The Bigger Picture) before telling people they either must or ought to be wearing these things.
Pete.