I think the revision of the NSFNet AUP in 1994 (?) to allow commercial use, and the decommissioning of the NSFNet in 1995, was what made the internet into a "monster". Even if people were "only" running NNTP, email, and anonymous FTP, the internet would have taken off massively at that point. This was obvious to me from the time I joined the internet in 1992.