But...I'm sure there would have been another worm or virus (and many others - like there had been) that would have caused the same vigilant info security that we have today.
The way I read it, the point was that "another first virus" wasn't likely to be designed as a benign proof of concept by a tinkerer who meant no harm. The author's view is that the Morris Worm was a happy accident in that it grabbed all the attention owed to the first virus to affect networks on a global scale but it did so without causing any real and lasting harm.
It's a fictional short story, so I am guilty of taking liberties in imagination :)
On the other hand, we did luck out that, when our systems were extremely vulnerable, the first attack to demonstrate those glaring issues was not intentionally malicious
Given the frequency with which the same mistakes keep on being made (SQL injection, IoT DDOS...) I don't think we did learn much, and the big headlines are still on the cards. Nice short story, though.