No, I do not think they are 100% secure, but you have to deal with that. Plus, as we are heading forward, I am sure there will be more safer and safer ways to participate in ICOs.
At the end of the day everything can be a securities, if the government wants to enforce it. For example, rewards points from big retail store, ebay, amazon, etc can also be considered a securities, however, the masses have agreed that it is not. Eth and btc are are securites, however, teh SEC have decided (because people are willing to agree that it is not) that they are not securities. So, everything is a security, which can be approved if there is mass adoption and support from the public.
I don't they had any choice in the case of BTC and ETH. Can you imagine that hanging on the books? They could use that violation as an excuse to do whatever they want, whenever they want, to anyone in crypto.