I think my 'always right' mantra bugs you because I have a better track record than you do.
Wii U is not a terrible product. It is a great product with no message to drive its value. All in all, its a product where you either get why the gamepad is awesome or you just hate it.
Hopefully Nintendo has learned why Wii with its unique controller was a stellar market success story and Wii U with its unique controller was not.
Wii was selling for over $400 on ebay for two years after launch. While WiiU was at $250-300 within months after launch. Nope not price.
Wii was basically a turbo powered Gamecube and its gap with PS360 is greater than WiiU's with PS4/XB1. WiiU also had the technical cability to run all of the same graphical technologies, at a lower scale of course, as PS4/XB1. Lack of 3rd party games was not lack of power, it was combination of barrier on developing games for WiiU's PowerPC architecture with no middleware support to allow simple scaling against its low install base. Wii's was lack of power, WiiU was lack of middleware to make easy ports.
WiiU OS is still faster, more flexible, better personalization and easier to use than PS360/PS4/XB1. There are some features WiiU doesn't do, but the user experience is better in almost every way, especially when you consider the gamepad.
Gamepad is not heavy, is a dual analog controller and allows you to play in far more comfortable positions due to off-TV support. ProController is crazy light and extremely long battery life. As with going between PS/MS, as soon as the layout is normalized to you, the controllers are very comfortable.
I don't see any differences playing same games on the different systems. COD is a perfect example that multiplayer is considerably the same between them all. Game sizes / team sizes / voice / etc are all the same. Only difference I can note is the party system that is built-in to XBL and PSN.
WiiU absolutely kills the others when it comes to exclusives. All of the games that people clamour about with PS4/XB1 are 3rd party. Nintendo lives on its own IPs. WiiU has a multitude of excellent exclusive content (as well as duds like SFZero).
Of course, content is where its value should have stood out. Content should have been able to demonstrate 1) this is not a Wii AND 2) I MUST play with the gamepad. That is the failure.
Summary, it wasn't a terrible product. It was an awesome product with a terrible vision and delivery. I think NX willl demonstrate why you want a controller with a screen.