Because new technology is as Thiel often quips limited to the world of bits rather than the world of atoms. Paul Krugman once asked, if you go into an average house right now and you take out all the screens, could you tell that you're not in the 80s? Gordon in the Rise and Fall of American Growth gives a similar example, what if you went into a time capsule between say 1890 and 1950 compared to 1960 and 2010? In one…
One way to tell whether you're in an 80s house would be to look around for reference books, encyclopedias, rolodexes, filing cabinets. If you wanted to know more about something, you probably had to go to a library, which might not even have a book on the topic (maybe if you were particularly determined to know the answer you'd wait a few weeks for an ILL).
Its a bit sad to me that you look at this enormous sea change in how we interact with the world and see Angry Birds.