We can only say that Ethereum is the king of ICO if there are good and valuable ICOs in the market. For the latest months is it difficult to say that there are good ICOs who are funding high amounts.
maybe Ethereum was king of Ico before because many ICOs could succeed and the project could run smoothly. for now many failed ICOs don't know what happened and there are many causes, maybe in the future ICO will get better and Ethereum becomes the king of ICO.