I don't think this is the correct way to think of things. I think there are 2 different cultures that have contributed to the computing world today. The first is from academics and big company research. This is the legacy of IBM and AT&T Bell Labs - hackers wearing ties.
The second is tha hacker culture of Woz, Gates and the rest who developed the PC, brought the rarefied computing of AT&T and IBM to the masses. I dont think its fair to say that the latter stood on the shoulders of the former, as much as they had their own unique contribution.
I agree that there are two different cultures at work here. One, that of PARC and Bell Labs, was foundational. The other, of MS and Apple, are transformative.
It is with the foundational work of folks like dmr that the 80s era computing companies were able to gain traction in the first place. Don't misunderstand, I'm don't mean to lessen the importance of the contributions Jobs has made to the computing industry, but he didn't live in a vacuum.
The idea that Apple, Microsoft, others, were built on the foundations set down buy the computing pioneers of the 60s and 70s is, perhaps, no more than recognition, and respect to the importance of that foundational research.
The second is tha hacker culture of Woz, Gates and the rest who developed the PC, brought the rarefied computing of AT&T and IBM to the masses. I dont think its fair to say that the latter stood on the shoulders of the former, as much as they had their own unique contribution.