Would that be a bad thing though? Those websites are purposefully acting in a way that doesn't respect the copyright of the owner of the content they want to show.
That they do this through a third-party host shouldn't be that important.
Yes. As a strong opinion holder in the copyleft philosophy of any and all content, I feel such sites have a right to exist and profit from content as much as the copyright holders (who are not necessarily the creators of said content).
But hey, this is just the opinion of some random dude on the Internet.
If what is and what isn't law was that clear cut, the case wouldn't escalate to the European Court of Justice. Add to that that laws are arbitrarily incoherent and therefore the decision is just one possible interpretation of the law, albeit one that will be upheld.
That they do this through a third-party host shouldn't be that important.