Steve has VISION.
When computers were DOS and worked with keyboards, he came up with the GUI and mouse. True, he borrowed those ideas from other companies, but who brought them to fruition?
When people visualized computers mostly as business machines, who made them fun to use in the home?
When portable devices meant mostly things like Palm Pilots, who came up with the iPod?
When they said it was impossible to come up with a music-selling business model that would satisfy customers and the industry, who invented iTMS?
No, he doesn't do the work himself. But he sure as hell knows how to point the company in the right direction.