The reason the Japanese cds work the way they do is that it is cheaper in Japan to buy imports than it is to buy domestic releases. So by releasing cds often a month before they're released elsewhere, & putting songs on them that don't appear on other releases, they encourage the Japanese to buy the domestic releases. Not sure why the Japanese labels' desires trump those of any other countries' labels, and yeah it is a drag, but that's just how it is.
Wasn't that long ago that people (myself included) would buy numerous import albums to get songs that didn't appear on the regular releases of our favorite bands, and there was no complaining about it; buying extra import issues has been a way of life for dedicated music fans for decades.