The author hints at, but does not point to, data that correlates motorcycle helmets laws with higher accidents. That is counter to recent research which supports the standard view that helmet laws save lives: https://www.sciencebasedmedicine.org/the-cost-of-repealing-m...
Short version: after repealing helmet laws in Michigan, they have seen higher injury severity and mortality.
I think you are mistaken. This is the quote from the article I am responding to: "Adams has figures to prove that countries – indeed US states – that do not require motorbike helmets have fewer biking accidents than those that do."
The research I linked to is also about motorcycles.
Short version: after repealing helmet laws in Michigan, they have seen higher injury severity and mortality.