Here's where the common usage of first and last name break down: his family name is Kim. I suspect it's along the lines of what you're getting at: to keep the name together.

I'm not sure how interesting this is in and of itself. It might be interesting to see if this is a special case. If it is, is there a particular reason for it? One could speculate all kinds of reasons, but I'm not sure how useful that is without actually knowing why.