1. Exit scams After raising millions of dollars they will eventually turning to scam. Or they saying that funds are hack etc.
2. Dead project coin becoming dead and don't have demand in market
Those two are both main factors why ICOs are now dead. Investors are now aware on how risky is the ICOs investment because of the scam projects where most of the developers are only focusing to gain profit and after that there is no improvement that will happen in to the project. The risks in ICOs are not worth it after all so we should learn from the mistakes of others in order for us to not make investment in ICOs anymore.