I know enough about the Madoff point to know that it can't be argued in good faith. Not unless you are willing to describe everyone who ever got looked into by the SEC, and then not prosecuted, as a scammer engaged in a scheme. Because that time scale requires the inclusion of investigations that found no fraud. Now if you are willing to expand your definition of fraud to include the whole of Wall St activity - then I definitely won't argue otherwise, sure - bitcoin is just like that except less concentrated and more transparent.

The larger point being that any plausible definition for fraud applied to crypto actually undermines the legitimacy of the modern financial system to a much greater degree.