Nintendo started training me to love handhelds when I got a gameboy color with pokemon in 97 (I believe) until then I had played only 2600/NES/SNES/GEN/N64 and since I have never missed an iteration of handheld gaming (even though I missed the 6th gen of console gaming).
But to your actual point :) I think that you are overthinking things maybe just a little. I believe Nintendo realized that the Wii remote (motion/IR) was played out as the main control scheme (I am glad that they kept them compatible with the Wii U as I plan to enjoy quite a few games with it in the future) so they went with another attempt to change things up (utilizing a large touchscreen making the controller into a gamepad).
I for one picked it right back up (the Wii Remote/Nunchuck provided an analog stick, buttons and dpad, and I played many games on my Wii with the classic controller so no biggie).
Anyways I am rambling TLDR version: Nintendo isn't trying to push you to the 3DS (or next handheld) they just tried to add in the same revolution they added to their handhelds last gen (touch) and it didn't make sense to put that on a motion controller.
Systems Currently Playing: WiiU, PS3, 3DS
Also Have: Atari 2600, NES, SNES, PS1, N64, PS2, Wii, GB, GBC, GBA, DSLite, DSi, Android (RazorMax), iPhone (4), iPad (2)
