I think they said something about it retroactively after there was some complaining. The thing is, they're right, people upgrade, but how large of a percent sell, trade, (or even stupidly dispose) of an old system and the power cord when they get a new one? A lot I would imagine, so it's not really a fair argument whoever made it first.
Sure it probably save them a dollar in parts, but that doesn't make it right. They've done it for quite a few handhelds in Japan, not sure what the reaction over there was as we don't really see it.