I dont think ethereum is scam, ethereum is already known like bitcoin. Ethereum is a crypto currency that helps everyone to have money. Many traders who invested in it already gained huge profit but i can't blame those who are saying ethereum is scam.
Ethereum is not a scam because nearly everyone knows about and a lot of the people are using it also. There are also many airdrops and bounty's for Ethereum so basically on these facts.
I can tell that ETH is not a scam and you can still use it safely.