Sure it is, just like the NES, SNES, and especially the N64 and GC. They all stopped selling after ~5-6 years so I guess they were all fads. Seems like Nintendo only knows how to produce fads.

Fads usually only last one or two years. So if it really only was a fad then it was one of the most successful ones of all time.

They haven't sold well considering the Wii console sales when compared to the 360 or PS3.
My point is that the wii is not for core gamers. No more heros sold just over 520,000....That's barely anything. 

 If the wii is for core gamers, explain the relatively low sales of core games on the console.

Why do I need people to defend me? The sales speak for themselves. 

My main Problem with the Wii was that it simply lacked substance. It was the first console in my life (started with NES) that I simply did not play with...

Lets look at the top 30 Software and show what Software somehow defined the Wii

1 Wii Sports
2 Mario Kart Wii
3 Wii Sports Resort
4 Wii Play Wii
5 New Super Mario Bros. Wii
6 Wii Fit
7 Wii Fit Plus
8 Super Smash Bros. Brawl
9 Super Mario Galaxy Wii
10 Just Dance 2
11 Just Dance 3
12 Mario & Sonic at the Olympic Games Wii
13 Mario Party 8 Wii
14 Wii Party
15 Super Mario Galaxy 2
16 Just Dance
17 The Legend of Zelda: Twilight Princess
18 Donkey Kong Country Returns
19 Zumba Fitness Wii
20 Link's Crossbow Training Wii
21 LEGO Star Wars: The Complete Saga Wii
22 Guitar Hero III: Legends of Rock Wii
23 Animal Crossing: City Folk Wii
24 Mario & Sonic at the Olympic Winter Games
25 Michael Jackson: The Experience Wii
26 Carnival Games Wii
27 EA Sports Active Wii
28 Big Brain Academy: Wii Degree
29 Guitar Hero: World Tour Wii 2008
30 Super Paper Mario

If I look for a substantial single player experience that I am only left with Super Mario Bros Wii, Super Mario Galaxy, Super Mario Galaxy 2, The Legend of Zelda: Twilight Princess, Donkey Kong Country Returns, Lego Star Wars and Super Paper Mario... Very concentrated on the Platform Genre and no Game with a Focus on story telling and character development. Of these Games I only played Super Mario Galaxy but I am likely to buy some when I have finally finished my existing backlog.

If I compare the situation with the PS3 I simply got more substantial games and more variety:

1 Call of Duty: Modern Warfare 3
2 Call of Duty: Black Ops
3 Call of Duty: Modern Warfare 2
4 Grand Theft Auto IV
5 Gran Turismo 5
6 Call of Duty 4: Modern Warfare
7 FIFA Soccer 12
8 Metal Gear Solid 4: Guns of the Patriots
9 Uncharted 2: Among Thieves
10 Battlefield 3
11 Assassin's Creed II
12 LittleBigPlanet
13 Call of Duty: World at War
14 FIFA Soccer 11
15 Final Fantasy XIII
16 Red Dead Redemption
17 Resident Evil 5
18 Assassin's Creed
19 God of War III
20 Uncharted: Drake's Fortune
21 Uncharted 3: Drake's Deception
22 Gran Turismo 5 Prologue
23 Resistance: Fall of Man
24 Assassin's Creed: Brotherhood
25 MotorStorm
26 The Elder Scrolls V: Skyrim
27 FIFA Soccer 10
28 Batman: Arkham Asylum
29 Assassin's Creed: Revelations
30 Sports Champions

I do not like Shooters and Sandboxgames and therefore I will not go into CoD and GTA/Red Dead Redemption. I personally enjoy Final Fantasy XIII, Metal Gear Solid, Uncharted, Assassin's Creed, Resident Evil, Little Big Planet and God of War. I simply have more variety and besides the gameplay I have story telling and character development aspects in the games.

So the Wii sold better, but it mainly sold games that are often lack substance. It is nice for beginners who are not into games because they can learn the games rather quickly. But as a single player experience it was underwhelming for me. It is sad but I bought more games from the Virtual Console than for the Wii. The Wii might have sold very well but the SNES was the best Nintendo console for me... Super Mario World, Zelda 3, Terranigma, Castlevania, Metroid, Super Probotector, Terranigma, Actraiser... (Unfortunately europe did not get Final Fantasy...).

So, we should look out, if Nintendo can convert Wii-owners to Wii-U-owners. That's something interesting to watch in the next year.

That's the point here. The Wii destroyed the competition early in the gen, but now is outselled by nearly the same percentage. You can say, that's because the successor is already on it's way, but that leaves the question: Why does NIntendo bring the successor so early, if they could have made money on the Wii otherwise?

I'd say that if motion controls DON'T make it to the next gen, then Wii was a fad! But as it seems WiiU still supports motion controls, and I find it hard to believe that Kinect is going anywhere. The Wii started something new, which seems to be lasting well into the next gen - and that's not fad like.

And guys, I don't care about core-games or casual-games (if such things even exists, I have a hard time to classify many games in this spectrum). I wanted to know if the HD-fans were right early in the gen claiming, that the Wii is a fad. Obviously it would made for a long fad, it lasted 3 years+. So, maybe the point is more about: were they right claiming, that the Wii can't last the whole gen? It seems something unexpected and new, that the winning console is outsold by it's losing competitors at the end of the gen by such a margin. Did that happen ever before in the console-industry?

hmm.. I think that might be hard, although I won't put it beyond Nintendo to surprise me here.

In my opinion a good part of the people who bought the Wii are satisfied with the experience they got, but don't feel they need more that quickly.. many of them are adults and adults are patient, so a lot of them might just sit out a gen before investing in new hardware (if they even feel the need for new games .. I mean I know a lot of folks, that just play Solitair for 20 years and are perfectly fine with not trying any other game).

1.  No, I addressed your point.  Several times, in fact, but apparently I have to again, so I'll keep it as simple as possible.  I, who am not a casual gamer, along with many others, find motion controls for games like golf, bowling, and tennis MORE accurate than using a control pad.  It's far more realistic and accurate when putting a spin on the ball or getting more swing with a stroke, similar to how it is in, you know, REALLY PERFORMING THESE MOVES.  Make sense now?  I realize it's hard for you to understand how other people's opinions can differ from yours, but alas, they do.

2. Your hypocrisy here is truly amazing, but your response is, again, easily refutable.  You are simply regarding PCs as the standard for games; saying that if trends (such as motion controls) are not prevalent in PC gaming, they're relegated to being fads.  I have pointed out how ridiculous that is by saying home gaming consoles, which are primarily about gaming unlike PCs, have embraced motion controls.  So again, I know it's hard to accept opposing viewpoints to your own.  Regarding the mouse example, how is it so hard for you to understand its relevance when you've already answered your own question?  Twice.  As accurate as a mouse is, it's not practical in the environment where gaming takes full precedence.  Yet, motion controls are.  Hmmmm...