The book, ghostwritten by Howard Rheingold in 1985, was a visceral crystallization of what I think is fair to call the punk era of hacking in the early 80's. Having just enough point of contact in personal computing to understand what was going on and just enough credulity to accept the wildness of the story, it was quite a captivating narrative. This book, a few issues of Electronic Fun with Computers and Games and a photocopied version of The Secret Guide to Computers were what really turned me on to computers as a kid in the 80's.
Reading a book like Inner Circle or an article like this may have provided a certain hero myth for hackers, the kind which sometimes seems necessary to kindle a long-term passion. A myth like what James Bond was to aspiring CIA operatives, Star Trek was to future JPL engineers, and now The Social Network is to Stanford undergrads. I think our society greatly underestimates how valuable these myths can be. Without an article about having a hand-held box that lets you put a worldwide communications network at your disposal, would there be an iPhone?
Exploring a complex system and trying to break it down to it's underlying rules is the ultimate engaging activity. It's a little less so when that system is man-made, though I imagine Ma Bell at that time was so large and complex that emergent properties had arisen of the system that no one knew.
The idea of riding the wires using your voice because you have perfect pitch does feel very Neo in the Matrix though. Going to have to watch that movie again as I tail -f some logs.