If the Wii U has a pointless gamepad, given it's a window into another world, just like Project Morpheus (minus 3D and side effects), given that 3D is gimmicky for most people and the side effects are rather on the bad side, it should fail miserably...
That said I think the Wii U Gamepad is a good idea that only lacks the New 3DS stereoscopy to make it better. I'd prefer that over any virtual reality helmet, because I'm not disconnected from my surroundings, something that matters a lot to me. [But I can understand some people want the exact opposite.]
I don't find the Wii U Gamepad to be pointless, but its been underutilized for sure. Very few games make great use of it. Nintendo started with Nintendo Land, and Ubisoft made fantastic use of it with Zombi U. Many games feature convenient features, but aren't really game changers. It is kind of funny though, Nintendo and Microsoft both focused a lot on creating a unique control interface that really could change the way you play games, Nintendo with the Gamepad and Microsoft with Kinect, and both of those gambles came up empty. Meanwhile Sony releases a new PlayStation that does little more than upgrade the processing tech, and its a smash hit. I think there is some truth to being a gamer that has been around for a long time, you start to expect that blow your mind radical change in gaming that happened with the N64, but that sort of radical change doesn't seem likely to happen any time soon. On second thought, it sort of did with the Wii when it first came out. Playing Wii Sports for the first time gave a similar vibe, but the control interface was limited to waggle for the majority of games, and therefore wasn't established for the core gaming experience. Zelda SS and Red Steel 2 were simply to late to really establish motion controls with traditional core gaming experiences.