Here's the real kicker: if I don't know where the country is, why would I care enough to google it? "Africa" in this situation gives me more info than the name of the country would.
You never look up things you don't recognize? I care to look things up every day, and before the web I used physical dictionaries and encyclopedias on a frequent basis. Some people may never feel that inquisitive, but quite a lot of us are, and I'd imagine most people on HN are like that.
There's a lot of articles posted to HN every day that I don't understand. If I researched them all, I'd have no time to actually do something productive. I skip them and move on unless something else about it catches my eye.