They're created because they've become the new fad in investing. Most of them are just ways for companies to get money from gullible or naive investors often for a company or product that is at best half-assed and wouldn't get investment any other way. There's no real regulatory body monitoring ICOs so most of them can do what they want and there's no repercussions if they screw up and don't deliver what they promised which is what seems to happen to most of them.