I do not think you are wrong, Avole ... I think the article you cited ans the study it cited are wrong. I think the headline is outrageous---Nothing about science can determine that bicycle helmets are "a must." that is just click-bait headline writing.
but ... if the hed was "a study shows that bicycle helmets could potentially prevent an undefined number of hypothetical fatalities" n one would click on it. So we get sensationalized pseudo-science based on junk science, and then people cite that trash as support for invasive and unnecessary legislation, or use it ti support arguments which didn't need to be started int he first place.
There is "right" and "wrong" in science---inaccurate data, incorrect data analysis, and claiming unsupported hypotheses to be proven. There is "right" and "wrong" in journalism ... again, inaccurate or misinterpreted data, false conclusions, invented theorems .... but in science and in journalism, standards have pretty much gone out the window.
There is no "wrong" or "right" about wearing a helmet.
However ... If I posted "person X does some unmentionable thing with a family member on a bicycle" and had nothing to back it up ... I am sure you could see why some of person X's family members might be upset, and even any decent person with a sense of honesty and propriety might be upset. "Let's not stoop to making unfounded accusations and imaginary claims here, alright?" Not many people would disagree I hope.
So, in this case, I say, Let's not stoop to making unfounded accusations and imaginary claims here, alright?
Wear your helmet if you choose, though. I have never in my life suggested that anyone not wear a helmet, or that there should be a law forbidding people whose chose to wear helmets, to wear them.