I don't know, I don't run Nintendo. I know it's not the answer you're looking for but there it is.
And, assuming they retrofit the account system onto the 3DS since full digital retail titles are coming, do you really think that layer of abstraction would vanish? Friend codes in use on that platform wouldn't vanish. Instead, we would likely have both an individual account system for digital purchase and friend codes for online games. Both can coexist.
That sort of implementation wouldn't make any sense with everything we know about the Miiverse and the online integration Nintendo has talked about.