The fact that there are still a lot of uncertain regulation that surround these funding sources mean that most exchanges simply wouldn't risk offering this sort of service/product to countries like the US, as squatter stated. However, I wonder how exchanges plan on ensuring that US based customers have no way of accessing this? Mandatory KYC?
Fundamentally speaking though, IEOs are really not that different from the traditional token crowdfunds that we've seen. Apart from the fact that the token is almost guaranteed to have instant liquidity on a big exchange.
I certainly would not view it as 'safer', especially when you consider the fact that you may see more manipulation given that vapourware can be easily sold, essentially.