The reason behind most new tokens being on Ethereum is Ethereum has a very good reputation in the market. Beside this blockchain is the most trustworthy one. So, people feel it more safe to be on this ICO.
But SciDex is also Best & Safe Because I Only Trust On SciDex, SciDex is creating a new contract that will be readable by human and machine, will be on the blockchain and can be used by normal businesses. And they are doing an ICO soon.