Jobs's reluctance to make the Mac compatible with the architecture of the Lisa was motivated by more than rivalry or revenge.
There was a philosophical component, one that was related to his penchant for control.
He believed that for a computer to be truly great,
its hardware and its software had to be tightly linked.
When a computer was open to running software that also worked on other computers,
it would end up sacrificing some functionality.
The best products, he believed, were "whole widgets" that were designed end-to-end,
with the software closely tailored to the hardware and vice versa.
This is what would distinguish the Macintosh,
which had an operating system that worked only on its own hardware,
from the environment that Microsoft was creating, in which its operating system could be used on hardware made by many different companies.
"Jobs is a strong-willed, elitist artist
who doesn't want his creations mutated inauspiciously by unworthy programmers," explained ZDNet's editor Dan Farber.
"It would be as if someone off the street added some brush strokes to a Picasso painting or changed the lyrics to a Dylan song."
In later years Jobs's whole-widget approach would distinguish the iPhone, iPod, and iPad from their competitors.
It resulted in awesome products.
But it was not always the best strategy for dominating a market.
"From the first Mac to the latest iPhone,
Jobs's systems have always been sealed shut to prevent consumers from meddling and modifying them,"
noted Leander Kahney, author of Cult of the Mac.
Jobs's desire to control the user experience had been at the heart of his debate with Wozniak over whether the Apple II would have slots
that allow a user to plug expansion cards into a computer's motherboard and thus add some new functionality.
Wozniak won that argument: The Apple II had eight slots.
But this time around it would be Jobs's machine, not Wozniak's, and the Macintosh would have limited slots.
You wouldn't even be able to open the case and get to the motherboard.
For a hobbyist or hacker, that was uncool.
But for Jobs, the Macintosh was for the masses.
He wanted to give them a controlled experience.