From my few hours of research on Xerox PARC, the laser printer did make a huge return (as you note, correctly); it's just "typical Xerox" that the engineers who invented LASER printing (i.e. using a laser to scan) also had to sit on their invention for years because the executive/sales teams didn't believe in an already-functional technology (the first decade of Xerox "non-ink printers" used visible light; the laser literally had to be forced into the Xerox equipment by R&D..!