I agree with most of these points, however, anecdotally I will say that my helmet prevented some pretty nasty facial road rash when I was doored a few years ago

I agree with most of these points, however, anecdotally I will say that my helmet prevented some pretty nasty facial road rash when I was doored a few years ago. I tipped and hit my head, and then slid ~10 feet. My helmet prevented my face/ear from taking the initial impact as well as the subsequent slide across the dirty urban asphalt. Helmets don't just protect from massive TBIs.