[ghaff]

I don't know if it's actually a plausible outcome, but take advertising out of the equation and you probably end up with a significantly more limited Internet that's mostly accessed from institutional accounts (as was originally the case) and by individuals who are fine with a fairly expensive subscription fee.

ADDED: I do tend to think the commercialization of the Internet with advertising was probably inevitable, but someone could probably construct at least a vaguely plausible narrative around a less commercialized post-NSFNET world.