I've seen this as a 'test' for the unsophisticated user a couple of times, and I don't understand the reasoning behind it.
I do almost all of my web navigation via search-bar and auto-complete.
It works quite well (this particular Facebook page is weird though).
This is mostly because I don't like managing bookmarks (Bookmarks get too cluttery if you actually use them as bookmarks... I only use them for temporary stuff like saving pages for a product i'm researching).
If I really want to find something and I can't remember the name of the site (which is a rarity), I'd just use browser history or search for keywords anyway...
I think that there is something ergonomically wrong with the way that we name websites. http://news.ycombinator.com/ does not stick in my head (it does not come to mind first anyway). "Hacker News" totally does, and it is easier to type.
I think that implying people are unsophisticated when they are really just lazy/apathetic about specific technical details leads you to the wrong conclusions about what type of things they can handle.