Lack of regulation and people eager to participate are the factors that attract scammers to do such thing. To put this in simple logic, there will be no scammers if there are no people that are falling easily to their scam. And these scammers exist because no one would stop them, or make them responsible, once they just quit and steal investors money. No authority is responsible in penalizing these so-called companies that are outright quitting. There's nothing sure in the crypto-space. From price trends (whale manipulation), to regulations and policies, and anonimity, it's hard to figure out since it's made decentralized.