It's not a metaphor. They both engage in referencing copyrighted material, but YouTube gets to skip out on the laws that appky to other industries.

This board is usually in agreement that patents that are effectively of the pattern of "were doing something that's been done before, but it's on the internet so it's different now" are complete bullshit.

Why are we giving a pass to internet based companies when it comes to copyright, just because they are making a lot of money?

No, Youtube takes a cut from the ads that are run on the videos of the creators. So they are directly profitting from the content. A print shop as metaphor would work if a creator would have to pay youtube to host his video, but all further proceeds would go solely to him.

If Youtube profits directly from whatever they are hosting it is not that farfetched to say that they might also be liable for what is shown