A follow-up quote from Gates's AMA: "The main 'copying' that went on relative to Steve and me is that we both benefited from the work that Xerox Parc did in creating graphical interface - it wasn't just them but they did the best work. Steve hired Bob Belville, I hired Charles Simonyi. We didn't violate any IP rights Xerox had but their work showed the way that led to the Mac and Windows."
To be fair, Xerox has probably done more copying than any other company in history.
There's a wonderful exchange from the STEVE JOBS movie that was never filmed. Paraphrasing here but close enough.
Interviewer: "What do you say to people who claim you stole the GUI from Xerox?"
Jobs: "Do you know who invented the piano?"
Jobs: "Do you know who wrote Moonlight Sonata?"
Jobs: "Well, there's your answer."
Wasn't this a scene in the TV Show "Pirates of Silicon Valley" over a decade ago?
Definitely recommend watching 'Pirates of Silicon Valley' if you've never it before, made for TV movie on TNT several years ago. Deals with the founding of Apple and Microsoft up until the mid 90s. Plus Noah Wyle is a better Steve Jobs than Fassbender ( and certainly Kutcher) imo. Seeing this post I'm somewhat surprised this is actually a quote from Gates and not just a line from the movie. Not sure if it's on any of the streaming services, I think I had to torrent a copy a few years back.