If developers want to roll back blockchain then how one can predict that before it actually happens? You can say that every project except bitcoin is scam, because any such project is basically centralized and its blockchain could be rolled back anytime its creators decide to do so. It is impossible to know before this happens. But what we can do is to catch them before they even started to sell their shitcoins. If they are copypasting other's ideas and doctoring team pictures, they are scammers no matter what they claim.