Investors like us can hold but ICOs need to sell cryptos to remain operational. The problem is that since the price of crypto fall, they will run out of fund much quicker. This also means that they are more pressured to sell their cryptos. And in large quantities if they feel like the price is gonna drop even further. However, that creates a chain where that will drop the price and pressure other ICOs to dump theirs as well. Now this vicious cycle won't apply to ICOs that are already profitable or diversified their fund. However, considering that most didn't, this is a serious issue.