That was nearly 20 years ago, when the entire internet was UNIX machines. (BTW, the bug was in a program (sendmail), not the OS.) The failure of Microsoft to learn from the mistakes of UNIX, which had a 20-year head start, is an embarassment.
If a bug in a program takes down the entire OS, which is what happened with the sendmail worm, then your OS has a problem. All the machines that crashed as a result of the worm crashed because they fell victim to what was effectively a fork bomb, and that's not a sendmail problem.
If 1988 was over 20 years ago, you are a genuine futurist.
I will not defend Microsoft against the charge that they did not anticipate the rise of the internet as a consumer appliance. I happen to remember 1995, when I first started using the internet at home. At the time the computer magazines were full of articles asking what the next killer app would be. No one mentioned the browser. So duh.
Microsoft concentrated its efforts on making networking easy for non-technical people, ath the expense of security. As a result, Windows has a 90 percent market share, and Unix in its various forms has less than ten percent. I wonder if Bill Gates and his stockholders would have it the other way round.