"I assumed that people who enjoy software would be into intellectual stimulation but I've learned that this is wrong."
It was truer in the 1980s-1990s, when programming was not a prestigious or high paying job and computers were much cruder and required much more skill to get adequate performance from them. Generally, aspiring hackers were very well read people.
There were, of course, corporate programmers doing business programming back then too but they weren't considered hackers and wouldn't even have wanted themselves to be considered hackers.