Ethereum has never been called a sinking ship, it will only become once people are abandoning the chain and projects are moving to another chain, but it's not the case so far, they may be quiet right now, and that includes the price but not for long, they are still on target once Ethereum POS start moving things are going to change.
Actually it has been called such a few times by a few people. If people have said Bitcoin can die, surely people will also say the same about ETH;) In fact, even when people talked about the ETH flippening I was still thinking this wouldn't last, but in the end I saw it had potential and gave in. (I bet ETC people said it would sink in 2016).