For the various obvious reasons. I mean to loot peoples money, get free money flowing into their wallets and never look back towards the project. The cheaters are growing at an alarming rate these days because they will pull out multiple scams one after another. For example, in the OP's case they might gain some money from the presale because there are always some people who will be buying blindly and thus scammers will will have a good balance at the end. They will pick this money and use it to create another big scam. This chain will keep on going because this is anonymous market and no one ever knows who is behind the scene. They dare because they know, nobody is going to know ever! Shits, always stay away from such projects.