To many scams but now is the fall of the market and it is really very difficult for all the projects to realize all their ideas. That is why there are so many scams.
Sometimes it is very difficult to say is it a real scam or simple the team was not able to realized all planned ideas because it was unexperienced. That is why it is very important to check the team and its experience.
It is hard to say why project has become scam and why it became a scam but in all the cases people lost their money.