Re: He shouldn't also forget that Steve said....
"Bill Gates for Windows claiming he'd copied Apple's idea to which Bill pointed out they'd both been to see the Xerox OS"
No Apple did not steal from Xerox, but Microsoft did steal from Apple. I don't believe Gates saw anything before Jobs demonstrated the Macintosh to him.
Douglas Englebart invented the mouse around 1963, not Xerox PARC. Jef Raskin at Apple was doing similar stuff to PARC and knew those guys. Raskin did his Ph.D in the 1960s on the graphics package that became Apple's Quickdraw. He was working at Apple doing similar stuff to the Xerox guys. It was Raskin who suggested to Jobs that he take up PARC's invitation to go and see what they were doing.
PARC invited industry players in Apple, Tektronix, and IBM to view their stuff, because they had been ordered by Xerox HQ on the East Coast to drop what they were doing - it wasn't Xerox's core business. Tektronix and IBM didn't get it. But Jobs did. And the Xerox PARC guys were amazed how Jobs got it, since Xerox, Tektronix, and IBM didn't. Some at PARC realised it was the end of the road there, so those like Alan Kay and Larry Tesler left PARC to further this technology at Apple. They went on Apple's payroll, so were rewarded for their efforts.
Apple still took considerable risks to develop this technology. The other part of the story is how PARC machines cost nearly $100,000, but Apple managed to put it in a machine selling for $10,000 (the Lisa), and then $2,000 (the Mac).
Apple also did not exactly copy the PARC interface. Pull down menus at the top of the screen were Apple's innovation.
Now Bill Gates did illegally copy Apple's stuff - particularly Quickdraw that was Raskin's.