"90% of people don’t know how to use CTRL+F to find a word in a document or web page."
Should they have to?
I still think Apple had it right with the original Mac keyboard. No function keys, no CNTL key, no command line. Everything had to be graphical. Then they went to UNIX.
I suppose the assumption was that "they use computers all the time", which wrongly was equated to "they use computers in a meaningful way all the time". However, at best, despite their often use of computers, that computer use has been superficial. Otherwise, I would have expected they would have encountered things like CONTROL+F and discovered the convention that you can use that shortcut to search in almost every program. However, somehow, these conventions and underlying concepts of desktops, GUIs, computers, and what not, stayed hidden somehow for most computer users.
Given the huge amounts of time spend using computers, I too expected people to have developed a deeper insight in how to use them. But, as others in this discussion have suggested, I suppose most people use computers only as a means to an end, not an end in itself. It is just a tool, like an oven, a mop, a car, and so on. They spend huge amounts of time using those tools as well without "mastering" them or developing a deeper understanding of them either. For example, unless you're interested in cooking you might cook almost every day without coming to understand cooking at a deeper level too.
I think the author's point was not about keyboard shortcuts but about the fact that people won't even know that the find feature exists (and thus they won't look in the menus/toolbars) unless they're taught.
Should they have to?
I still think Apple had it right with the original Mac keyboard. No function keys, no CNTL key, no command line. Everything had to be graphical. Then they went to UNIX.