Target audience is a big factor too, I think the article failed to emphasize this. And, secondly, the nature of what is being documented. Do you remember when there used to be entire sections of bookstores dedicated to books like "Learn to use Word 98"? These books were always incredibly thick, so one time I opened one to find out how there could be so much to write about Word 98 (or whatever it was). Turns out it wa…
Those books weren't much use in learning how to use the software. They were just easier to produce. They never explained the ideas behind the software. They just showed you the user interface. They treated everyone as if they didn't know how to use a menu. Things are often the way they are because that way is easier to produce, not because it is useful.
Yes, and that's OK - somebody had to do it for hundreds of millions of people!
My own first summer job long, long ago as a student was helping a small company transfer some paper "business processes" and calculations to Excel, and that involved teaching Excel to a few people double and triple my age. They generally had few issues with Excel itself, as they had worked with paper spreadsheets in pre-computer accounting, but a significant challenge was mouse skills, because as it turns out, if you move the pointer where you want to, lift your hand up, and press the mouse button, then as you press the pointer will slide away from where you wanted to click.. so that took some time and practice.
Don't take things for granted. People weren't born knowing how to use a mouse or other tools. Everything that's universal now had to be painstakingly learned once, and yes, these materials did have to teach people how to use a menu, because that was relevant for much of their target audience.