I dont think that closing them will help at all. ICO's cant be closed as we are in the decentralised space and there is no way to control things up here.
If you see this as problem then we should be clever enough to identify the problem and fake ICO's. Learn from the mistakes of yourself and others and then try to judge the best out from the crowd.
That might help.
But removing the ICO concept is illogical or impossible.
In short Bitcoin is freedom of choice and forex is not. Forex runs with the technical data that is provided by the exchanges but in case of bitcoin the whole market can be moved depending upon the investment that gets into it. There are no shady things in this world as every dam thing here is public and when it comes to the trading of coins then its full transparency. That is why choosing bitcoin trading or crypto trading would be always great.