My impression is simply that people don't know Japanese geography, which isn't all together too surprising. There's no reason a person should know the geography of Japan any better than the geography of Uzbekistan if he or she doesn't have a specific tie to either country. They just hear "earthquake in Japan" and ask the people who live in Japan if they're doing alright.
My brother lives in Auckland. We had a lot of people asking if he was OK after the quake in Christchurch. They are ~700 miles away on different islands, so he wasn't affected at all by the quake there, but we patiently explained this. It seems silly to get so haughty when people are expressing genuine concern for your well-being.