"Friend codes" represent absolutely everything that is wrong with Nintendo's attempt at developing an online community that is literally a decade behind every other console and two decades behind computers. Yeah, I remember having to type in friend codes on the PC, in 1995 I had to type my neighbor's phone number in to play Command and Conquer online with them!
There was a time when connecting to the Internet involved a computer generating a set of tones and broadcasting them through actual telephone headsets using a set of speakers that slotted into the headset. It seems Nintendo wants to recreate the nostalgic feeling of this era.
I blame Nintendo's failure on the absolutely deplorable state of their online platform and congratulate Valve for their ability to mobilize their entire community to vote for them. Some mods have enough trouble getting their members to vote for them on moddb's mod of the year contest, Valve's ability to motivate their customers is simply put, amazing, and every company looking to develop a great online community should take a long hard look at Valve. For Valve, it seems developing the community is nearly important, if not as important, as making the games.