Jef did go on to create a computer along the lines of his original vision after leaving Apple.

> The Canon Cat used a text-based user interface, without any pointer, mouse, icons, or graphics. All data was seen as a long "stream" of text broken into several pages. Instead of using a traditional command-line interface or menu system, the Cat used its special keyboard, with commands activated by holding down a "Use Front" key and pressing another key.

https://www.wikipedia.org/wiki/Canon_Cat

It was nothing like the Macintosh Apple shipped.