The decline in Ethereum price has been both spectacular and also shocking. With Bitcoin down around 4% yesterday I was seeing Ethereum down by about 15% it seems to be the hardest hit of any of the coins at the moment. The only reason I can think of is that because it is the main currency used for ICO funding, many of the projects are panic selling their ETH stacks to try and retain some FIAT funding.
What you speak of is definitely one of the contributing factors, couple that with increasing competition namely from EOS, Stellar, TRX etc and the landscape for ETH is just very different to how it was a year ago. I think by 2019 ETH will no longer be the no 2 coin.