I am very curious to see the actual numbers because I have heard of many many crooked projects using public and private funding through traditional methods like IPO's, crowdfunding, etc. I dont have any data to back this claim up, but I don't think there is much more scammers with ICO's than there are using the traditional system. If anything I would assume that the crypto community online is actually slightly more educated and skeptical when it comes to these things so the rate may actually be lower with ICO's than IPO's and scammers who convince private investors out of money for start ups.
Moral of the story is that its always risky when youre giving someone that you dont know to well your money, hence why it shouldn't be 100% about the money when you invest. Invest in a better world and lets elevate each other.