This anti-ETH sentiment is caused by competitors like EOS and Cardano who market themselves as Ethereum killers. Last year everyone loved ETH and criticism was very rare, but now that competitors have launched their networks, the FUD bombardment has begun. I personally wouldn't be 100% bearish on ETH, I think in some very long run it will lose to BTC, if Bitcoin will get smart contracts, sidechains and other features, simply because Bitcoin is more decentralized and secure, but in the shorter perspective ETH at least has some proven track record of developers doing their job, while its competitors are still very young.
That's a good point, there are many out there who would benefit financially from making ETH look bad. It's not as unstable as they would like it to appear, probably. It's also got a bit of seniority in the very young market, which is commendable (although not a good enough reason to make it invulnerable).
It doesn't look like it's ready to go anywhere, but it just might not be as hyped up as we thought it was last year. Although we could say similar things about other altcoins, even bitcoin as well. The reality check stage is starting to hit, and that's why everyone is working hard to make their coins have real world application and trust.