Eh, I don’t think the correlation of age is the causation of getting wounded or killed due to questionable decisions on powerful motorcycles. I’d venture to say the correlation is moreso in personality type, and aversion, or lack thereof to risk.
Like, you don’t see complete straight edge 16 year olds getting bikes, and from my own anecdotal experience, my straight edge friends were scared of it. Though if there wasn’t an inherent aversion to the risk, I’d bet those types would be incredibly safe motorcycle drivers.
The types that currently get them are the types that will take risks, regardless of their age, and we can’t rightly outlaw something because some risk takers act dangerously on them. We’d have to outlaw cars too.