His quest for perfection led to his compulsion for Apple to have end-to-end control of every product that it made.
He got hives, or worse, when contemplating great Apple software running on another company's crappy hardware,
and he likewise was allergic to the thought of unapproved apps or content polluting the perfection of an Apple device.
This ability to integrate hardware and software and content into one unified system enabled him to impose simplicity.
The astronomer Johannes Kepler declared that "nature loves simplicity and unity." So did Steve Jobs.
This instinct for integrated systems put him squarely on one side of the most fundamental divide in the digital world: open versus closed.
The hacker ethos handed down from the Homebrew Computer Club favored the open approach,
in which there was little centralized control and people were free to modify hardware and software, share code, write to open standards,
shun proprietary systems, and have content and apps that were compatible with a variety of devices and operating systems.
The young Wozniak was in that camp: The Apple II he designed was easily opened and sported plenty of slots and ports that people could jack into as they pleased.
With the Macintosh Jobs became a founding father of the other camp.
The Macintosh would be like an appliance, with the hardware and software tightly woven together and closed to modifications.
The hacker ethos would be sacrificed in order to create a seamless and simple user experience.
This led Jobs to decree that the Macintosh operating system would not be available for any other company's hardware.
Microsoft pursued the opposite strategy, allowing its Windows operating system to be promiscuously licensed.
That did not produce the most elegant computers, but it did lead to Microsoft's dominating the world of operating systems.
After Apple's market share shrank to less than 5%, Microsoft's approach was declared the winner in the personal computer realm.