Investors are risking legal and criminal culpability for illegal selling on unregistered exchanges.
why eos is a security?
This sounds like little more than FUD. ICO coins might be securities, but they were issued before the the ruling. China delisted their cryptos, but they are not legaly prosecuting anyone for selling them legitimately. The US can't stop people from having ICOs in other countries and they can't shutdown the internet to stop anyone from selling them to whoever wants them.
Expecting the SEC to remove ETH? Sounds like the people who told me the 'Deep State' would ban BTC. More and more exchanges are going to go decentralized if anything.
FWIW, this Epicenter podcast episode contains fairly good perspective from an attorney with some knowledge on the SEC & how they think about things like ICOs in the context of the question: "can project ____ be considered a security?"
Epicenter #198: Nick Morgan: The DAO, the SEC and the ICO Boom
Note: this only addresses the perspective from within the United States. With regards to Chromatic's point about ICOs worldwide, I tend to agree.