ICOs are securities and should be registered as such or properly filed as exempt. Unregistered ICOs are currently being used to skirt securities laws, and anyone doing that should be viewed with the maximum amount of suspicion. It may be unfair to label all ICOs scammers on account of a few, but it certainly is not unfair to regard anyone issuing an unregistered ICO as someone attempting to avert regulation, and therefore suspect them of not acting honestly. There is essentially no difference between an ICO offering and a securities offering, except the ICO doesn't grant ownership rights to the business raising the funds, and so ICOs (in my view) are generally bought into by people who aren't sophisticated enough not to be taken advantage of.