The "greedy victim" is the typical explanation for fraud, and the article touches on this:

  He makes mercifully short mention of the usual explanation—
  “greed” on the part of ordinary people trying to get “above their
  station”—which has been trotted out after every financial fraud
  for the past 300 years.

The article makes the point that Americans get ripped off disproportionately, that there's something about American culture that either encourages or doesn't punish flimflam, Ponzi and confidence games.

Is it the ethic of rugged self-reliance? Or the idolization of entrepreneurs and the ultra-rich?

I bring up religion because America is much more religious than other Western countries, and it seems like people who believe without evidence might be more susceptible to confidence games.