Cases like Napster [0] and Grokster [1] set precedence for this sort of thing. They also used the DMCA in their defence, and they were still found culpable. These were decisions that were scoped by the method of delivery, so if YouTube was going to stop giving everyone a great deal, they'd be betting they have a solid case as to why their technology is legally distinct from those examples, and many others. (And conversely, like instances where the safe harbor clause has been used in a successful defence)
That's a weird bet to take when the benefit is... people stop complaining about YouTube Content ID, and find something else to complain about?
The Napster decision left the DMCA question open as it didn't affect the actual appeal, and was instead left to be decided at trial (which never occurred):
> We do not agree that Napster's potential liability for contributory and vicarious infringement renders the Digital Millennium Copyright Act inapplicable per se. We instead recognize that this issue will be more fully developed at trial.
Cases like Napster [0] and Grokster [1] set precedence for this sort of thing. They also used the DMCA in their defence, and they were still found culpable. These were decisions that were scoped by the method of delivery, so if YouTube was going to stop giving everyone a great deal, they'd be betting they have a solid case as to why their technology is legally distinct from those examples, and many others. (And conversely, like instances where the safe harbor clause has been used in a successful defence)
That's a weird bet to take when the benefit is... people stop complaining about YouTube Content ID, and find something else to complain about?
[0] https://en.wikipedia.org/wiki/A%26M_Records,_Inc._v._Napster....
[1] https://en.wikipedia.org/wiki/MGM_Studios,_Inc._v._Grokster,....