It's intellectually lazy to conflate things into "HUGE PENT UP DEMAND" or "NO DEMAND WHATSOEVER" and completely unrepresentative of real life.
You can continue throwing around terms like "anyone with common sense" and "deluded" while cowering inside your absurdly reductionist binary totality all you want, but it makes your analysis piss-poor.
The WiiU obviously has some demand. More so than a PS3 on Amazon UK right now.
Demand isn't purely a function of cost. Some people paid full price for the premium day one, and were happy with it, some people will never ever buy a WiiU at any price.
The PS3 never recovered its sales because it had one big must have killer app that everyone could point to; it recovered due to building sufficient amounts of small reasons to own one for most people over time. That's how the market usually works.
Seeing what both Ps4 and Xbone are offering are some "small reasons" that will have persuaded some consumers that were closer to the fence to now buy.
A price cut (that's been seen before at other retailers, and at a greater amount) from Amazon is also a "small reason".
Sticker shock when the other consoles finally show their hands are also "small reasons".
Pikmin 3 getting released will be a "small reason" for some.
This isn't Rocket science. You might want to decouple your own perspective of the WiiU - which is obviously that you see no point in buying it - from a broader perspective that the majority of consumers do not have enough reasons to buy it.
Whether they ever do is not something that can be predicted on current information, but I would expect to see an NPD and Medacreate uptick now that the wiiU is actually competing against products and not dreamlike-wish-fulfillment-vapourware.
EDIT:
actually probably not mediacreate, because the percentage of people who would have cared about the xbone in japan falls into the "margin of error" percentage of consumers.
This. Many consumers went Wii &/or 360 only when Sony screamed the "$599 U.S. dollars" pricetag. Same can happen between Wii U/PS4/Xbox One in which many consumers may wind up going Wii U only due to bizarre news like "blocking used games" on other consoles.