Their JP playerbase is larger. You can look at the forums as a clear example. This post has the support of probably everyone here - and it only has 60 some-odd likes. When a JP post has the forum support, there's 400+ likes. That's a pretty big difference. NA isn't the same size playerbase. SE wants to grab as much money as they can from us, but you are kidding yourself if you think that our subs are anything but gravy on their JP mashed potatoes.