Not sure if he's serious, but not including AC adapter is in line with EU political trend (environmental reasons). It isn't really bad, most households have a tons of adapter, often the same multiple times because of all the handhelds, phones and what not. This really needs to stop.
It's annoying that the exclusion of the adapter doesn't result in a cheaper price though.
And to be fair, my dad bought an iPod nano, and it came without an adapter as well. It's nothing new here.
Apple portable devices always comes with their own proprietary cable in the box, so you can still charge and sync the device. You can't with the 3DS XL, but there's a chance you do have a adapter that's compatible, if you have a DSL, DSi, DSi XL or 3DS.