I often wonder to what extent scams like this have positive externalities, insofar as the people who get scammed were perhaps unlikely to allocate capital in socially efficient ways.
From a game theory perspective, I believe that dishonest players are always a net negative for all other players. It might seem that it's good when capital transfers from stupid to smart people, but actually it moves from honest to dishonest people, which results in less efficiency. All this capital is now used to perpetrate more scams, which means that more capital will be allocated to these scammers instead of something honest. And because of these scammers, all honest people have now less capital to work with.