While I don't know about rear-facing seats for outcomes, having cycled recreationally and for commute for the last 10 years, wearing a helmet has on multiple occasions saved me (yes I understand anecdata of 1) from mild lacerations to letting me walk away from a 40 mile downhill crash with road rash. Cycling without a helmet is a personal decision, but I don't understand how you can argue that increased head protection does not improve overall morbidity and mortality.