Indeed we must learn from these mistakes. Whatever comments we make on the project do not really affect much, they are gone and what we can only take is the mistakes we make. In the future, surely we do not want to promote a project that is not so good.
Our comments will do something to the project if they failed to meet their promises to us. If you get scammed do not keep silent but tell the world how you get scammed and tell them to stay away from that project. With that not only you can prevent other people from getting scammed, but you also can get rid of some of your frustration.
after doing that you can learn from your mistakes and make a proper research in the future to prevent you from getting scammed again.