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
For me, it's very important it is where you can access everything you need to know about the project, this is why in the service section creating a whitepaper command a good price from freelancers and this is where investors looked to check if the project is worth investing.