One of the major differences between Ethereum and Bitcoin is that the whales are much more active towards Bitcoin, it was the first cryptocurrency on the market and some of the whales never left the boat. Whales probably had an impact on Bitcoin Cash too last year, but in general they target Bitcoin.

So the difference when we talk about altcoins in general is that what they need is a lot of hype to gain value. Remember Ripple last year.

But because market cap is very low for a lot of them, only the hype will make them gain value, it's easy on paper but the competition has became really fierce, and most importantly atlcoins have suffered from bad publicity this year. That's why it's difficult right now, and this includes Ethereum too.