I agree, and yet that's what happens. Such is the absurdity of Ponzi schemes and the way they turn large numbers of otherwise intelligent people into irrational morons.
Have you considered group conformity effects here? If everybody around them is insisting that they're an idiot for even thinking that BS&T is a ponzi and that only stupid people don't understand BS&T's business model, even a lot of intelligent people are going to irrationally go along with the group consensus. There is literally no such thing as a non-irrational person. Doesn't exist.
Why wouldn't this apply equally to everyone who deposited money with Pirate? If we can assume that every reasonable person must have known it was a scam, then everyone who deposited money with Pirate was paying Pirate to steal money from others and give it to them.
It should apply to everyone who convinced other people to invest money in Pirate and insisted that all the people calling it a Ponzi were trolls.