Who is protecting the buyers at the moment at an ICO? Is there usually an escrow?
How can you compare investments and trade? it's a lame and absurd comparison 
Investing in an ICO is like playing the lottery, if you are lucky, you have a lot of money, otherwise you lose it. But trading is another aspect, if you give the money to the lottery ticket seller, and then they say you haven't given the money, what do you do? It's completely different, don't make such a dumb comparison. It is the duty of each trading platform to protect their customers from scammers. Once a customer and business establish a business reputation there would not be scamming just like a normal business. Exchange can't stop scammers, biggest scammers in the world are exchanges. wait until bitcoin hits $1,000,000 and they will run off with your coins and claim they got hacked. Please say that shit to someone who didn't get 100 bitcoins stolen from mtgox.
ETH and Exchanges were the worst that happened to crypto.