It was a fascinating idea - programs were hidden behind a document template metaphor. It was not as neat as Windows “New” menu and its templates folder.
Also kind of makes sense out of the concept of "Desk Accessories" (i.e. the things under the Apple menu in Macintosh System 1 — Lisa OS also had these.) Every Lisa OS "task" (there were no processes in the pre-emptive sense) is either running a program in the context of a document that program manipulates; or is a document-less accessory program, running under some other task.
Also kind of makes sense out of the concept of "Desk Accessories" (i.e. the things under the Apple menu in Macintosh System 1 — Lisa OS also had these.) Every Lisa OS "task" (there were no processes in the pre-emptive sense) is either running a program in the context of a document that program manipulates; or is a document-less accessory program, running under some other task.