The Internet was designed for use within research establishments where
people were all, at some level, accountable and trustworthy. It has
become
a playground for con artists and pests.

All, at some level, accountable and trustworthy? Not really. The first
spam was in 1978, so there were problems from the beginning.

There was very little until the 1990s, and if the first spam was in 1978,
then we had about 7 years of good networking before there was any.