He was a demonstrably bad CEO, so much so that the Apple board fired him. He then went on to get better at the job through running another two companies until, eventually, Apple purchased one of these companies (it was very much unsuccessful, BTW). Then he became CEO and the company and was, finally, phenomenally successful.
Also he died 15 years ago, but Apple's success (measured in market cap at least) went up more than 10x since he died (from 300-400B to 3-4T), under Tim Cook. That's arguably from the groundwork and reputation the company laid down 15 years ago, but still - few companies manage to keep growing on stuff they did 15 years ago. Oil industry notwithstanding.
And since we're talking about CEOs, top-level personnel decisions are one of the biggest impacts a CEO can make. SJ promoted Ive to director of design, he also hired and eventually promoted Cook to COO.
The CEO is in large part responsible for picking what products have hope to grow the company. The iphone was far from a slam dunk, many thought it would fail. Now it's responsible for over half their revenue and they're one of the largest companies in the world.
>Then he became CEO and the company and was, finally, phenomenally successful.
I'm totally confused by your post, so you admit he became a good CEO then?