When the Wii U was first being conceived, Nintendo wanted to make it a console that could appeal to current Wii owners, newcomers, and experienced "Core gamers". The Wii was a massive hit, but it was often stereotyped as a casual and non-gamer console with an abundance of fitness games, party games, and mini-game collections. Especially since more and more developers were moving into HD, and thus, moving their projects to PS3 and 360.

So with the initial Wii U reveal, Nintendo wanted to make sure that the Wii U would be a console that can bring the core gamer back. The controller being a standard gamepad with a screen on it, games like Darksiders II, Batman Arkahm City, and Tekken announced to be coming to the console at launch. EA's "Unprecedented Partnership". It seemed like Nintendo was using the Wii U to make the Wii brand cool to PlayStation and Xbox gamers.

https://www.youtube.com/watch?v=upgzaZ5nk-o

I'll never forget. Nintendo seemed to drop that after 2013 when AAA third-party support died.
The initial framing at E3 events and other PR by Nintendo as Wii U for being more for "core gamers" is so laughable.
Due to the slow clock speed and less than ideal architecture, third-party Wii U games were almost never superior to Xbox 360 and PS3. In fact, some performed worse (Arkham City has more frame drops). This is sad because the Wii U's RAM and GPU are far superior to the 360 and PS3 (though not close to Xbox One or PS4).
In addition
-Online still sucked (just like it does on Switch). How are you focusing on core gamers (or any players for that matter) when you don't have a solid and easy to play with and socialize online service?
-The GamePad was forced. Most core gamers don't want a big tablet with a touchscreen forced on them. There should have been SKUs of the Wii U with no GamePad and the Pro Controller instead.
-Paltry storage. 8 GB is almost entirely useless, and 32 GB doesn't cut it either. Xbox 360 and PS3 had SKUS with 120 GB and up. Since the Wii U can support external hard drives, then why didn't Nintendo include an internal hard drive too?
And those are the key takeaways. Ironically enough, Wii probably has a lot more worthwhile games in its library for core gamers than Wii U.
Switch is pretty much the perfect combo for all types of players.

Even more ironic is that the Switch has all the same problems as the Wii from a "core gamer" perspective.

* It's still woefully underpowered compared to PlayStation and Xbox.

* It still doesn't have great online.

* It still has a bunch of gimmicks

* It still focuses more on family fun time with multiplayer and motion controls vs. a "hardcore" gamer experience

* It still regularly misses most of the biggest AAA third party games. And if they do come, they're often late watered down "impossible ports" or cloud versions.

Yet in spite of all that, I think the Switch is seen as less of a joke to "core gamers" compared to the Wii purely because it's also a handheld. That makes it less easy to compare to and scoff at since Nintendo was always better at being a portable platform holder vs. a console one. As such, the third party support and graphics are a lot more impressive for the Switch as a mobile system. Because as strictly a home console, it's kinda lame compared to the PS5 or Xbox Series. (And I say this as someone who loves the Switch.)

PS3-level graphics and ports of PS3 games were never going to satisfy Playstation crowd

Nintendo was completely lost at that moment

It's because Switch follows the standard control schema. No more mandatory motion controls nonsense like Wii did. If you plug a Switch on your TV is just your standard console, with slightly better PS3 graphics but a console still. 

I mean, the Joy-Con are basically successors to the Wii Remote and Nunchuck. Of course, they don't have the same limited button layout as those controllers, so you are correct that you can more easily use the Switch as a normal console. But motion control is still a big part of the system's identity, with a lot of first and third party games offering motion control options, or some games requiring them. Even if it's not "the point" like it was with the Wii.

huh??

1. It's not woefully underpowered. It's a handheld. You can't compare the power of handhelds and consoles.

2. Sure it doesn't have great online I'll give you that.

3. No sure what gimmicks it has. Being able to play anywhere isn't a gimmick, just the coolest way to make a system.

4. Have you played the Switch? Motion controls are barely used, and definitely not a focus of the system. And since when did gamers not enjoy "fun time with multiplayer"?? lol. "Hardcore gamer" is not just deathmatch shooters. Many many many first party and third party games on Switch are "hardcore gamer" games.

5. Yes it misses most of the big AAA third party games because those companies almost exclusively make those games for the latest high end graphics which is of course going to be for consoles and not a handheld system.

And you think Switch is seen as less of a joke to "core gamers"....uhhh, who in the world would ever think of Switch as a joke?! lol. It took the gaming world by storm and has many of the best games of the past 7 years exclusive to it.

Wii's problem was the 100% focus on motion controls which, while awesome, is only awesome for certain kinds of games, so that being THE primary play mechanic of the system made it more of a casual system than "core gamer" system. Switch has almost no focus on motion control or any gimmick, it's a pretty ideal system for core gamers outside of big third party action games.

1. Yeah, that's my point. As a handheld, it's not too big of a deal. But as a home console, it's very weak compared to a PS5 or even a PS4 pro.

3. I mean look at the default controller. Candy colored detachable motion controllers that can each be used for two players with an IR Camera and HD Rumble. Tabletop mode alone. Gimmicks aren't a bad thing, but let's not pretend the Switch is a super conventional system.

4. There's plenty of motion control supported games on the Switch. It may not be the primary focus anymore, and very few games straight up require them compared to the Wii, but they're still a big selling point of the system. I mean, two of the biggest Switch releases this year are motion control-oriented (Samba De Amigo and WarioWare.)

I love the Switch, but if you use it exclusively in TV mode, then it really isn't that much better than Nintendo's last four home consoles in that it's yet another underpowered, gimmicky Nintendo console with that regularly misses the biggest third party AAA games. It's a GameCube 2.0 in that regard. However, as a portable and handheld system, the Switch is a great platform, and arguably one of Nintendo's best.

The importance of motion controls on Switch is overstated, there are a few titles that make heavy use of it to make motion control abense dealbreakers. From major software only Ring Fit Adventure and Switch sports come to mind, and at this point we can easily affirm Switch Sports was almost inconsequential to the console's success. On the other hand, handheld titles with virtually no use of motion controls are major contributors. Historically handheld-heavy titles like Animal Crossing and Pokemon coming to Switch did wonders for its overall success and popularity. Switch giving the option for gyro aiming is alright for people who like this crap, but not centering their design games around motion controls is their biggest wave to 3rd party developers and "hardcore" gamers alike. 

Of course, few games straight up require motion controls compared to the Wii, and it's not the main focus of the console. But it's still a big part of the system's appeal as there are still plenty of games that support motion controls or are designed with them in mind (like ARMS, Mario Odyssey, No More Heroes III). And several of the best selling games on Switch focus on Motion (like Ring Fit for example).

The Switch is successful in part because it's able to seamlessly accommodate these different play styles (Handheld, traditional games, touch, motion) that it allows it's library to have something for everyone.

Also, Gyro aiming is not crap...