It happens when the language is used not as a primary language, but more as a secondary language or for show. For example, you're in a country that isn't an English-speaking country, and you see plenty of English usage all over the place, like the menu, or random books. Sometimes there isn't much of a consideration into whether the English is properly used or not, because maybe there isn't much emphasis on whether it's correct, but there's more emphasis on whether it's used or not. Sometimes it bothers me, but other times, I just let it go.