What's wrong is the idea that there's such a thing as an "atheist culture." There isn't.
Look, get this straight: being an atheist means not believing in any god. That's it, nothing else. No doctrine, no beliefs, no dogma, no culture -- nothing.
As for "a woman being sold..." I think you'd better have a look at history. Christian societies have been doing this as long as there have been christian societies. It took breaking away from christian rule to get women equal rights.
Peace.