He massively overstates the consistency back then (selective memory probably), and also consistency is bad actually, when it's used without thought.
There were lots of inconsistent keyboard shortcuts between applications of any complexity. Icons weren't as consistent or obvious as he makes it out to be. Various menu items were sometimes here, sometimes there, and inconsistently named. Is it called "Preferences" or "Options" or "Settings"? Usually it was "Edit > Preferences" but not always. Lots of stuff has no obvious logical place at all in a hierarchical menu structure.
So why is "Preferences" in "Edit" with copy & paste and other document editing functions anyway? Those are not related really. Imagine reading the manual/tutorial of your favourite text editor, and it had a chapter "Basic Editing Functions". It tells you about copy, paste, delete but also somehow about how to set the background color, because, you know, one could argue that setting the background color is editing your preferences and so it should go in the chapter "Basic Editing Functions". But I guess it has to go somewhere so there it is (except when it isn't).
Even stupider is when applications adhered to the "File, Edit, ..." type menu when they weren't even working with files, and there was no document to edit either. Consistency for the sake of consistency, a cargo cult basically.
And don't get me started on the fine motor skills required to navigate these menus. Move the pointer a couple of pixels off the generally pretty small item, a whole tree of submenus might just pop out of existence.
I do like his list of rules/guidelines at the end though.