They needed to get it from the start. If they had that grand idea, we would have seen it at launch. The Wiimote had things going for it that the Pad don't. Namely novelty (we hadn't seen anything really like it before. People have been using tablets for years) and ease of use. My 60+ year old dad had never touched a video game in his life. He was able to grab the Wii Mote and play golf, bowling and tennis in a matter of seconds. This would not be the case with any tablet/TV interface. There was something much more natural about the Wii-mote as a method of input that the Pad simply cannot replicate.
I agree to a degree, in that I think the Wiimote was a much more basic design, and was able to get it's "message" across more clearly and much more easily.
Maybe you guys are right, though, and maybe you can logic it out to the GamePad being incapable of having the same appeal as the Wii Remote.
I guess I can use a phrase from Kevin Smith's "Too Fat for 40" special. In it, he tells a story about Wayne Gretzky's father giving his son a piece of advice for his hockey skill that can, theoretically apply to life itself.
"Don't go where the puck is, go where the puck's gonna be."
Maybe the Wii Remote was Nintendo going where the puck was going to be. They were bold, and aimed high to try to do something truly unique before anyone else really ventured before.
The DS was the same, in that sense, since it had touch screen gaming well before it was the norm.
Now, the Wii U, maybe that is Nintendo going where the puck is, in a world where touch screen gaming is the norm, and everyone plays Cut The Rope on their tablet.
I still think great software can turn the situation around, but Nintendo needs to look at the Wii U's eventual successor as another chance to revolutionize gaming again. They need to figure out where the puck is gonna be, and go there.