Personally , I don't think there should be an ICO without whitepaper. The whitepaper bridges the gap between an investor and a company. Can we say a ICO without a whitepaper is a scam? Or what can you say about an ICO without whitepaper
Unfortunately the whitepaper is the very important part this you can see if the project is scam or not by just reading on it, and the investors want to see the whitepaper first because all the details regarding on the project should be written on it so that if there is no whitepaper then don't invest, one more thing sometimes whitepaper is copy paste from the work of other so it was very important.