The only reason why some IEO were successful in binance and kucion was because the projects are really great but then again price will still plunge when real investors gets in while tokens are readily available in the market. It does happen every time in ICO. I think this is just to cut the bounty hunters out. Right now there are still ICO while IEO also exits so both are still working.
IEO will make bounty hunter sad, good project prefer use their fund to list their projects in reputable exchanges such as binance or another exchanges.its more effective and make investors trust to their projects.