My favorite argument: the internet has far less of humanity's knowledge on it than most people believe. There are so many major gaps.

Not only does expertise and apprenticeship for many trades and crafts still exist almost exclusively offline, but also the documentation of accomplishments and the state of the art for so many fields.

Google Books, the greatest library in the history of mankind is collecting dust behind a locked door due to copyright. The failure of Google Books (an ambitious, incredible attempt) is imo one of the biggest tragedies of the information age.