I take the risk of repeating something, but I would like to add an extremely important factor that makes stealing almost the only option for invention. This factor is ROI, the return on investment.
In my career, success never came in the way like in movies: brainstorming young guys desperately want to find out something, and wow, it happens! No. That is serious effort, lots of time. Real innovation is going out to the wild without maps, following only faith and motivation, not plans and sales figures. Real innovation means failure. Lots of failures because EXPERIENCE must be built up to tame the unknown, and only THEN come the results.
In our world this means bankruptcy. The investors stop funding the experiments, the researchers themselves lose their faith, the story has a bad ending. But the experience, the partial results remain. And there comes a new team, that picks up the "failure" with new investment, and finally succeeds. You can call it stealing, but it puts the bad taste at the wrong place. The monetary system, and the natural business motivations forces the innovation into a path of a multistage rocket.
From my point of view, Jobs did not add anything to the ideas from PARC (mouse, GUI, OOP, etc.): they were invented and put together fine. But at the same time, they looked like crap, were insanely slow and expensive. They simply did not seem to worth the effort buried into them, and I assume nobody wanted another turn in the the dollar auction. They showed it to external guys because they did not see any value in them. However, Jobs started to believe that it can change the world, had the charisma to get new team and new money into the story, was able to motivate or force his people to break their own boundaries, and finally (after desperate struggles and lots of pain) he won.
Being frustrated by this process is the same as being angry with gravity. I myself do it several times when I drop something, but it is still pointless... :-)
