It's been argued that the profits from the laser printer paid for the money spent on PARC a 100 fold. I'd agree with that. That said, I don't think Xerox could have been the new IBM/Microsoft/Apple combined - simply because their sales force was.. addicted? to the per imprint commission model, and it would be a huge change to go to a different model for them. So while PARC could have invented it, and they could have possibly gotten it into production, I don't think their existing sales and support force understood enough on how to sell and service it.
http://www.amazon.com/Dealers-Lightning-Michael-Hiltzik-eboo...