I think you're stretching it a bit.. If you truly want to blame anyone (the concept of blame is stupid anyway since I don't believe we have such a thing as free will) meaning you want to find the cause of the effect then you can't really ignore the actions of the victim. Like with a ponzi even here they must have seen ample red flags and warnings by other skeptics and yet decided to risk their money. And once you are in a risk vs reward scenario and the reward doesn't pan out and instead you experience the risk event you were expecting some of the time I don't see how you don't carry partial blame for losing your money.