I think you may have missed the point, and I apologise, if I didn't infer your thought as it was intended.
At any level of the stack, the hacker mindset of "learning how things work...(and utilizing that knowledge)" is generally applicable.
It's arguable that while, say, Steve Jobs wasn't a technically adept hacker, he was a business, product and people/behavior hacker.
I am aware, and I agree.
> Being a hacker has nothing to do with how far up the stack you operate.
I disagree. The workings further down the stack are interesting only to hackers, and those paid to work in that area. I think that's quite different from the reasons for interest further up the stack.