Everything you said that I didn't bold is true.  Price and complex hardware were big problems, but once those were fixed - boom no more issues.  Nobody asked for the Wii U -  It is too weak, has too few games, doesn't have enough modern features, and yes costs WAY too much.

The PS3 didn't have some tablet nobody wants jacking up its price.

The PS3 had a lot of potencial and raw power, which lead to a lot of improvements.
The WiiU, not so much...
However, the WiiU is kinda cool, I don´t know why people don´t buy it.

Maybe Nintendo thought they can make another "Wii" - with just new stuff.

Sadly, they didnt realize that like 80% of the casuals who bought the wii moved on.
BUT!! They did it with the 3DS - but it only sold like 1/3 of what the DS done.

Wii U - Gamepad
3DS - 3D

The massive 2012 loss for Sony was when they mixed games in with TVs into "Consumer Products & Services".  The next year they broke it back out and showed an Operating Profit for both 2012 and 2013 for "Games" alone.  It is also using Net Income for Nintendo instead of Operating Income.  In terms of Operating Income Nintendo was still showing losses for 2013 and 2014.  As well as the first 6 months of the fiscal year ended 2015, though they are pretty negligible losses this year.

The problem is that the wii-u has not third party support, the ps3 always had support...

But it lost Sony a lot of money on the PS3, and that's why it is ultimately a failed concept.

Honest question, do you think Sony thinks the PS3 was a successful concept?

It's because the PS3 was actually competitive to its biggest competitor. It was never far behind and still received massive 3rd party support. Also it was riding on a giant legacy with the PS1/2 that in the end scooped up most of its fans from the past.

Nintendo's core fanbase just isn't as big so I wouldn't know where they would turn the Wii U around to. I mean if Wii U manages to sell 20m this gen it pretty much has most of its fanbase back and it will never sway any non Nintendo fans due to lack of 3rd party and being completely underpowered.

The ps3 had a massive core userbase to tap into and the Wii U doesn't.

Lets look at the ps2/gamecube/xbox gen. There were 180 million gamers who bought an xbox/ps2 and 22million gamers who bought a gamecube.
The ps3 had a rough start which allowed the 360 to take a massive marketshare compared to last gen. But since the total potential customers is so huge there was enough room for both consoles to sell well. 

Now with the Wii's case it seems pretty clear that it didn't really steal many core gamers from the ps2/xbox crowd. This gen there are 168million xbox/ps3 gamers. Only 10 mil less than last gen despite how well the Wii sold. The wii kept all the nintendo gamers and also managed to get a massive amount of first time gamers to buy the wii. This new market proved to be huge but has almost completely moved on. Most of these people are certainly never going to buy another console in their lives. Especially not a console without a super cool new gimmick. The wii u gamepad doesn't seem like anything special considering touch gaming is nothing new. So now the wii u's only market is big nintendo fans, gamers who buy every console, and little kids whose parents aren't willing to buy them the other consoles. This as we can see is not a very big market.

Sony didn't turn around the PS3, the PS3 outsold the 360 every year since its launch. The only people who tell you otherwise is American's as they think America = the world in which the 360 outsold the PS3 in US & UK but world wide PS3 won every year which is how the 360 with a year head start ended up becoming last in console sales

Also the US Media was bashing the PS3 like crazy, saying this in that like "360 outselling PS3!" "PS3 going to be 3rd place this gen" "Blu-ray Sucks" "Cell processor #&@*"... But in EU/JP the PS3 was doing well as such it was actually outselling the 360 since launch.

America does not = the world, even though John Key thinks so but nobody likes him well maybe American's do...

So you aren't getting my point.  When I say that the Wii U was a failure in concept - [Another Wii with a Tablet as its gimmick] - I mean the very idea was a failure.  The PS3 had a sound concept - [A premium media console].  Even at its higher price point it sold completely out for a couple months and moved FAR more units than the Wii U did after its launch (Even before price drops).

In fact the point is that people need to stop comparing things to the PS3.  The Wii U for instance is on track to lose to the Dreamcast.  Comparing them only tell me a person doesn't understand the situation.