I am awared that there are scam ICOs but I do doubt that it is on as high percentage as 90%. maybe, 20% would be more rwalistic since based on my experience, 1 out of 10 ICOs is a scam. Or maybe, it just happen because of fortune and misfortune. Scam projects are surely hard to determine at the first glance and usually, it would be too late to notice.
Some ICo were really legit, it just usually didn't get their goal that others tagged them scam or tget didn't have much knowledge yet to run an ICo, choose wisely always.