what is the usage of Ethereum? creating ICOs.
I disagree with this statement.
The whole purpose of ethereum is NOT to creat ICOs.
The real purpose is to be able to create small programs (smart contracts) which can be executed without a central authority.
Just because the majority of people are using them to simply create ICOs where they just build some kind of a payment token and promise a lot of utility, this doesn't describe the usage/purpose of ethereum itself.
Most people are greedy. Thats the reason we have so much shitcoins and tokens now. They all just want to make fast money.
But this does no way mean that the whole ethereum network has been made for this one purpose.
Pretty much. Just because it's currently mostly being used for ICOs it doesn't automatically mean it was made for that sole purpose. It's just like saying bitcoin is being bought solely for speculation and not for transactions(which what it was made for).