This again? Tablets and phones are no substitute for sitting in front of your TV with a controller. Not to mention console gamers are bigger and better.
Who wants to play Mario or Zelda exlcusively on a tablet?
On your first point, typically I prefer a controller but tablets are a better input method for games like Sim City/Game Dev Story. On your second point, I wouldn't mind playing a Mario/Zelda game exclusively on the Wii U Gamepad, with the option to switch back to the TV if I so choose. My couch is far enough away from my TV that for some game experiences, I find it easier to use Off-TV Play.