It's an easy money. What else do they want? To be honest, people are buying ICO for one purpose only. To get quick money. They grab token as much as they can and dump it when it hits an exchange. That's natural here in cryptocurrency market. You have to be fast. So you won't be left behind. Some ICOs after hitting an exchange doesn't recover after massive dump. So better dump it before it's too late. Investors doesn't care much on the development. That's why in this environment only the best project survives and weak projects dies.