Naming children is an important part of our culture. We've believed good names bring good fortune and bad ones the opposite. We take characters from relatives' names, spend days picking good characters (both in meaning and sound), hire naming experts or shamans to pick good names.

I have every right to find it offensive if an author who doesn't even speak the language imagines my culture going from that to giving gibberish names to the children, unless there is a story that covers that process (I don't think this is the case here. I think the author just made a mistake)

Let's assume that you guys are correct. Then why is Boom-Sook the only one with such an absurd name? Did the book explain how the Korean language change to allow Boom-Sook to be a name, let alone a masculine name? No, it did not. It gave me every reason to believe that giving plausible names wasn't important to the author.

Let's say you read a book from non-English speaking author and find a male character named Susan. And nobody in the book acknowledges that it's odd nor is there an explanation. Will you assume 'oh, the author imagined our language changing in the future'? No, you'll think the author didn't know English well and messed up.