Well, that's because they want to get rich quickly without thinking about the risks, and the main factor in this is greedy, but lazy to find information about the truth of their investments. because of this, many people are exposed to scams on HYIP or Ponzi sites.
that is one of the scammers trapping investors, by offering huge profits quickly, and of course investors will also be tempted without first researching the project, a lot of projects like that these days and many investors experience losses
I think the legit project never offered huge profits. Scammers know that today or tomorrow, they will leave. Scammers need first investment but legit projects only care about products which can't possible in a short time. In history, any project can be left in any situation. Greed and trust is the main problem, to earn early profits investors got scammed easily.