Only 321k? Damn, that's actually pretty low. What about all those stories about 700,000 units shipped? 321k is less than the 3DS, which was totally overpriced and a massive flop.
I think you have the definition of "flop" wrong.
The Virtual Boy was a flop.
The Adventures of Pluto Nash was a flop.
The 3DS is not a flop, especially with the recent price cut and actual games getting released for it that weren't ports/remakes.
EDIT: Also "selling on a loss" only really digs you into the shit when you can't sell software/accessories to fill in the gap. 3DS software recently has sold rather well.