While Xerox invented the GUI and other technologies, Douglass Englebart at SRI invented the mouse and Henry Edward Roberts designed the first PC, the Altair 8800
https://en.wikipedia.org/wiki/Computer_mouse
https://en.wikipedia.org/wiki/Ed_Roberts_(computer_engineer)
My point still stands that they developed technologies outside of their core business focus but it didn't mean that their core business focus changed
While Xerox invented the GUI and other technologies, Douglass Englebart at SRI invented the mouse and Henry Edward Roberts designed the first PC, the Altair 8800
https://en.wikipedia.org/wiki/Computer_mouse
https://en.wikipedia.org/wiki/Ed_Roberts_(computer_engineer)