ICOs for anonymous projects are illegal and it is still going on, I have not seen any litigation related to these projects as these projects are unknown owners.
For projects with clear owners and company registrations, the ICO is legal since they have registered the company in a country that allows an ICO to be held, usually an ICO comes with AML / KYC standards.
For projects that are legal like you said, they will not be afraid to lose interest from investors by choosing to do ICO over IEO. Because experienced investors certainly know which projects are legal or at least sponsored by registered companies.