For me.
Ethereum is the best platform for ICO. only a few ICO tokens from other platforms. I like ICO from ethereum, many successful tokens at ICO to use the platform if the team is serious. Another reason is to easily manage only one wallet to store many tokens. Bitcoin is crypto number one in coinmarketcap. The crypto world always depends on bitcoin. So many people call it the king of crypto. The other side of ethereum is crypto second position. Most ICO projects use the ethereum (ERC-20 coin-based) platform. So many people call it the king of ICO.
And almost all ICOs use the ETHEREUM platform. And when someone hears ICO, then the next is ETH for them to install tokens or coins that the project has.