Honestly, it has no stigma from the mainstream market. It's totally unknown to the mainstream market.  Only a minority of the hardcore market has ever had an interest in NIntendo anyway.

Mainstream isn't always equal to what people on this site think and feel. A large number of buyers are families, young couples, people who buy 2 games a year tops, e.g. demographic profiles that are under-represented on this site. Those are the folks to whom Nintendo hasn't completely lost engagement.

The Wii U's future can change. It won't be a runaway success like the original Wii or the DS, but it can achieve N64-like greatness where it doesn't sell as well as it's competitors, but still finds it's foothold in the market.

If the Wii U had comparable or higher specs than PS4/XOne, would it not have the problems it does now?

I own a Wii U and I do not consider it truly "next gen" it falls somewhere between a PS3 and PS4 just like a Wii fell somewhere between a PS2 and a PS3

Well it comes down to games. Nintendo have about 5-6 games a year coming out for their consoles so no one thinks of them as serious competitors because their not.
Sony/Microsoft will eventually be launching 3 games a month at least like they're doing with Ps3/360 so yeah it's very easy to have Nintendo ignored when all they have are 5 games to be excited for.

It is part of next-gen.

You cant assume a comedy show is representative of anything else than comedy. Putting Nintendo there wouldnt be comical. They want to make Sheldon look like a geek. And theres a huge battle between PS4 and X1 since they released almost simultaniously.

You would realise they have played on the Wii on past episodes. The Wii U just wasnt relevant for the plot.

Why do people keep asking this stupid questions? :S What do you think?

This Gen's ignoring of Nintendo is a combination of what happened last gen and its poor sales performance exacerbating the problem.

Last Gen, the "console war" was fighting for second place, since the Wii was irreperably in the lead, any criticisms toward it couldn't hold water despite being true because the facts don't matter when we are talking about popularity.

When the Wii U came in by itself, it failed to make the impact of a new generation, so by the time of the PS4 and X1 release, the Wii U was already under the radar, not to mention its "competition" with the last gen consoles. It completely wasted its lead.

Virgin only worry about console wars

Moderated,

-Mr Khan

The WiiU isnt going to be to many peoples main system, for example i have the optiont o buy Watchdogs on my ps4 or WiiU well ill tell you this i wont get it for the Wiiu, its not that the WiiU is a bad system its just i like the ps4 more for mainstream titles, i bought the WiiU for Nintendos games and thats all ill own on it.  Thats the perception problem Nintendo has right now.  Until they decided to try and compete on the same field as Sony and MS or do something better then them they wont ever be considered a main system for core gamers, and its obvious that the casuals havent bought into the WiiU like they did the Wii.  Nintendo needs to try and make a system as powerful as sony and MS system, and they need to have the 3rd party support for that system.  right now they just dont have either of those things.  with that said I LOVE PIKMIN 3  i dislike NSMBu  3dworld is fun as hell though.

Generations are not about power, they are about time.

Because Nintendo has made themselves irrelevant.

However, I'd like to point out that the show has shown them all playing Wii (sports, MKWii, etc) multiple times as as soon as MK8 or some other game launches, likely they'll be playing that too.