The Average Person has no concept of How Things Could Be Better. They just take what's available, get the job done, take their paycheck and live their lives. iPad seems to be the first time that Average Jane is saying things like "it'd be really nice if more of what I need to do could happen on my iPad." Maybe it's not to the point of consumers actually driving demand -- such as demanding text books in digital form -- but it's a start (and a welcome change from people just accepting the status quo.)
The reasons from iPad's success and other tablets' failures are irrelevant to my point. Would the rest of the industry have eventually figured out how to make tablets marketable to all of humanity? Perhaps eventually, but the world we live in today, the one where tablets (specifically iPads) are in demand now is the one in which we live.
"...probably would not exist if it wasn't for Steve Jobs." Exactly. And also if not for Steve Wozniak. And if not for Bill Gates. And a handful of other people in the industry that worked with and competed against each other early on in their careers.