All-in-one electronic devices separate us from the real world, “connecting” humans only digitally.
A smartphone isn't unique, novel, or interesting these days — especially when it comes to saying something about a person. It doesn't prompt spontaneous conversations in the real world. The same isn't so with a book, where you can make public what your mind is doing, and even what you're interested in, to your immediate surroundings.
Single-purpose devices or objects are also more valuable than sharing “statuses” on Facebook or Twitter, because those platforms lack context and broadcast your life to a broad audience that thus couldn't care less. Without situational context, and with insular networks of people enforced by inflexible computer logic, it's near impossible for interesting, fulfilling chance encounters with new people as you go about your life.
I realized this when I was reading a paper book at a restaurant today. A waiter came up and said, “That's a great book.” We had a short conversation about the author and other books he'd written. This conversation would never have happened if I was reading it on my phone or e-reader.
As always, before inventing or adopting new technology, question what tangible problems it solves, and pay attention to little lovely forgotten aspects you might have to give up in the process.