China only prevented people and organizations from laundering and scammers. Since ICOs are established and China really let ICOs in their country, I think the best way to do is investigate those who are scammers and let them outside the organizations. You cannot prevent or stop people in using or investing in alt coins. There are many alt coins that people have trusted for years.
Yes you right! but I think this ICO ban in China is just temporary because cryptocurrencies is an opportunity and Chinese people are also using this crypto, maybe they restore the ban if they resolve that problem and bitcoin value will rise again.