I would add Xerox deciding not to market the PARC computer system because they were a “reproduction machine company. Would have hit the market years before Apple and Windows with an icon based, WYSIWYG, point and click system and with a laser printer.
Xerox invented basically everything about modern personal computers, from point and Wickard to intuitive interaction to bit mapping to ethernet to laser printers. But it’s unfair to say they blew it by not marketing their prototyp. The cost would’ve been prohibitive. It’s not a personal computer if persons can’t afford it.
IBM contrarywise got lucky. It hit at the exact optimum moment. You can’t plan that.
I meant point and click; don’t know how that happened.