There are videos out there where CHM interviewed Bill Atkinson. One part has him go over old Polaroids of Lisa interface drafts. There, he justifies the menu bar at the top of the screen differently: they couldn't figure out what to do when the menu was too wide.for the window when the user made it narrow.
Huh. I wonder why they thought this was such a big deal. I mean... the user caused the problem, and could easily fix it by enlarging the window. Other windowing GUIs handle this just fine.