All one needs is a seed.
My seed was planted on a closed system: an Atari 2600. Specifically, one with a Spectravideo Compumate keyboard. http://www.atarimuseum.com/videogames/consoles/2600/compumat... When I did as much as I could do on it, an Apple ][ clone was the next step.
When the iPad came out, I lamented the closed platform, forgetting that my Apple ][ was not where I started.
Something similar to my Spectravideo for iPad, is Codea http://twolivesleft.com/Codea/. Instantly accessible, and instantly running your code. A perfect seed for a kid who might express an interest in programming.
Any kid who discovers a passion for programming has options to move onto any platform their desire takes them. The ubiquity of the iPad and other tablets might even promote the introduction to programming to anyone who is curious enough.
Also, would people would stop calling an iPad a consumption device. It can be used this way. Many people do. But then, many people use their PC for little more than web browsing and to watch Netflix. It's not the platform, it's what interest them. My laptop is gathering dust because of my iPad.
The naturally curious will naturally do more within existing constraints, and then break free of them.