Because they have legions of rabid fans who not only buy their products regardless of quality, but act as an army of apologists for them. The result ironically,

Because they have legions of rabid fans who not only buy their products regardless of quality, but act as an army of apologists for them. The result ironically, is that unlike Sony's harsh lesson learned around the PS3, Nintendo has no such backlash to fear. The worst they can do is just own the portable market, and sell a few iterations of a console to their diehards, which are numerous.