>>14020143
Basically, they tossed whatever was "unnecessary" at the time. What little new copies were left of DS games at that time were spared (you can't exactly sell a cart only game as "new", but then again you can't exactly call a gutted store-bicycle copy "new" either, if you ask me), which was mostly shovelware/licensed shit, Pokemon Black 2/White 2/Conquest, and a few unsold remnant of older titles here and there (I managed a "new" Solatorobo at one for $15 at the time). Pretty much every used copy saw everything but the game itself trashed to make more shelf space, and more disgustingly, it wasn't just for new releases of games for actual systems, but also shelfspace for phone shit. And they had the gall to act like you should feel lucky they even had the cart only copies. I suspect the idea was that every other cartridge based system prior, few had cared if they kept the manauls and carts for (which ignores that those used flimsy cardstock while the DS has hard plastic cases). Of late, they've apparently made more of an effort to keep copies of DS games together where space permits rather than continue a blanket "into the trash it goes" policy, but apparently when they need more space, those cases, covers, and manuals are the first to go.
Anyhow, the point is, in an effort to make more space, they fucked the aftermarket for complete copies of a number of games. Gamestop having driven out so many individual used game stores over the years limiting local options for preowned games, they've thus caused much lower availability of complete copies, which admittedly affects various games more than others. Some have been lucky enough to see "launch-tier" reprints from their publishers, or third party online retailers (there's some canuck one that services NA), that come with everything the games should (shrink wrapped case, game, cover, manual; don't think first print bonuses are included though), but obviously not every game out there gets that treatment. Ones that were hard to find in general before have become that much harder to find complete, and more expensive too, thanks to Gamestop. It's one thing when a customer tosses the "extras"; it's another when the retailer does it themselves.
Also what >>14020187 says, though I think they generally wait until they stop stocking for something entirely before destroying the games themselves as well. I could be wrong though.