how did Nintendo left the Wii U there to die?

If they actually did, they would have already stopped development of their games for the consoles and announced the next one (NX doesn't count, a real presentation of their next console, not just a reminder for "hey, we're not fleeing the console market and going to become a smartphone developer" where we don't even know what NX really is)

If someone left the Wii U there to die, then it's the third party publishers. Nintendo did very much to get them back on board, as could be seen by the launch lineup with almost 20 non-Nintendo, Non-Indie and Non-Virtual Console games. But sales where low because most of these games where already out for some time, horribly optimized Xbox 360 versions with no extra incensitives (and in some cases, even cut content) to make them sell on the new console. So naturally, sales of these games where very bad and then their publishers jumped ship when they realised that 1-year-old games with no bonus or a lowered price attached don't sell a console.

Nintendo is still developing quite a few games for Wii U, and for sure also some yet unnanounced games. But they can only do so much alone. At least the Indie Developers are still there and some of their games are very good (Shovel Knight, Shantae and the Pirate's Curse, Giana Sisters Twisted dreams to name just a few gems)

Strongly disagree, as a longtime Nintendo fan the Wii didn't feel like a betrayal at all, in fact it was the happiest I've been with any console since the SNES.

So the Wii U will die without Zelda U? LOL no comment

While it's true the Wii had mountains of shovelware, it also had:

Xenoblade chronicles
Super Mario Galaxy 1 and 2
Super smash bros: Brawl
Monster Hunter Tri
Tatsunoko vs Capcom
Super paper mario
Lost in shadow
Fragile dreams
Arguably the best version of RE4
Pandora's tower
Kuon: The Grudge
The Last Story
Muramasa

And a whole bunch of other games too, as well as new peripherals, hardware refinements (wmp then wiimote with wmp included), and a fairly varied library of games, not just "kiddy" games.

If you think the Wii "stabbed nintendo fans in the back" more than the gamecube did, i have news for you..

I wouldnt consider a controller as HW refinement

And as for stabbing fans in the back, its all subjective if thats what he feels it it what he feels

when wiimotion plus released, it was an addon, when they changed that to put it into every controller, it became a refinement, int he same way that dualshock 3 being sold seperately was an addon until they started bundling it with the control instead of the sixaxis.

No, it is completely unreasonable to claim Nintendo stabbed fans in the back with Wii. If someone didn't like the console or games, that's fine, it still doesn't mean Nintendo betrayed anybody.

Nintendo published titles like Mario Galaxy 1+2, Metroid Prime 3, Twilight Princess, Xenoblade Chronicles, Donkey Kong Country Returns, among others. It's impossible to claim such titles aren't high-quality regardless if one likes them or not.

i guess but they didnt make motion+ controller standard until  way later in its life basically by the time the system was done and there wasnt really enough games to make it that relevant, but thats just my opinion

I think for him it was Ninty going the whole family route that might have him believe that they left core gamers out in the cold. I dont really agree and I can only speculate but, its kind of weird to say its unreasonable to think so. Maybe it is. Lets hear why he thinks so.

I didn't like the Wii at all but I don't think they intentionally went after the casuals. I think they tried to make a console that would appeal to the mass market while still releasing games for their core fan base and they did just that. Sadly, some of the more dedicated gamers didn't really like the whole wii mote thing and it quickly turned them off and then the casuals moved on to other things leaving Nintendo in it's current state where only the die hard Nintendo fans are left to support their home consoles.