Azhraell on 31 March 2014
Handhelds never have had high software ratio. 3ds and Vita both have almost the same according to this site (3 if I'm not wrong) and they sell a good amount digital.
As for Wii u, right now is not so high because the big games are not out yet, but it will most likely end up with similar ratio to snes and n64. That's the most it can get with almost zero 3rd party support. Responding to your question, their sales are not horrible, are good enough for them to make profit.
