Perhaps a better expression is that he helped popularize computing.
He did introduce a class of devices/products but Apple and Computational machines are not two concepts I associate.
The Windows OS has done more. My point being... yes he's a genius but in terms of Marketing, Business and seeing where the hockey puck is going.
He excelled at selling to desires, but look at the 'real computers' Apple has produced in recent years.
put another way, a lot of the _reason_ that companies like facebook and google are doing any computation in the first place is because of the level of data and interaction that people are doing on devices made by apple. You are welcome to make a distinction between a Cray and a MacBook pro, bu it is kind of pedantic.
If being able to create the 'end use software' on these devices, then again you're right.
If these devices are little more than portable web browsers, computing ?
Spend hours and hours going through the unedited version of history and judge for yourself. You can see the birth of many industries(Youtube-Mac Streaming, Google Search - Sherlock) in those keynotes and its refreshing to see it done so well. I'm not saying Jobs succeeded at all these things, but he definitely saw these things way way before anyone.