WiiU had many good games at launch and through the first couple years. Problem was its pitch. No one knew what it really was until it was too late. Additionally, it was marketed as a purely kid/fun console which worked for Wii due to Wii Sports. WiiU had no Wii Sports. Nothing to overcome its misunderstood first impression, price, power, etc.

While I argue WiiU had good games, it had no Wii Sports, ZeldaBOTW, SMBO, Halo, etc. WiiU never really got that one game early that made everyone say, "holy shit you have to play this".

I would agree that yes, hardware and initial marketing (first impressions are a bitch ~MS) are very important. However, all that can be overcome with at least one or a couple signature games. Content sells consoles.

Wii came out with most people like wtf and yay kiddie. However, Wii Sports very quickly changed that impression. Then that was followed up with many other fun and great content.

PS1 and 2 had that similar touch. They nailed the right first impression and then secured the big 3rd party games, most of which as exclusives, as well as some solid first part that was unmatched at the time. PS4 had the help in that MS failed the first impression, horribly. So that when people compared the very much identical game library, the price and first impressions won out in PS4 favor in a big way.

Switch is once again hitting the right first impressions and of course the perfect signature content. BOTW, MK8D, Splatoon2, SMBO. I'd argue greatly that had BOTW not been a launch title, Switch would have 50% of its current sales or less. The concept was intriguing, showing Zelda and Skyrim in the premier video was very smart, but... the price was shocking, the power level was disappointing, the battery life was hurtful, and the online plans are cringe-worthy. Literally ALL of this negativity was short-lived and pushed aside due to BOTW.

At the core, you are wrong. Content will overcome almost any negative the hardware or marketing screwed up.

But its not, its not important for Switch and it wasnt for DS/Wii/3DS,  also for PS2 that was weaker than GC and OG Xbox. Wii U would be failed even with power (Wii U failed in evre way), fact that I have mentioned you 4 gaming hardware that were successful proves you are wrong.  For Nintendo much more important is to have new or different experience compared to competition, like Wii and Switch.

Power on those systems wasnt a heldback. The balance betweent power/hardware reliability/price is important to not heldback sales, is like a triangle that has to be really well distributed. If it get unbalanced things cant get very ugly, like x360 RROD, ps3 launch price or Saturn lacking power for 3d games. People tend to think power isn important, but think if Nintendo ever cameback to making NES hardware and saying "our development efforts are now focused on NES hardware again", they would get a huge backlash. What im trying to say is, power just stop being important when they are not holding anything back.

That's cool. I don't want to argue. Let's hug!

Switch is around 3x weaker than PS4 and costs $300 without game while you can buy currently PS4 1TB LE console with one game for same price, but Switch like hybrid devaice has great value despite its weaker and actualy more expasive than PS4. Using NES like example is lame, but for instance Wii was literally upgraded GC, while PS3/Xbox360 were 20x stronger than Wii and Wii outsold both much more powerful consoles. It easy to see that power is not important if you offer something different compared to competition (again Wii and Switch are examples), but if you have two almost identical consoles for same price of course that power will be important (XB1 and PS4).

Hug. :)

PS4, Strong lineup.
Switch, Strong lineup.
Xbox One ...

But the market was literally divided between Hardcore and casual that gen, and both x360 and ps3 did well and at later in the gen started outselling Wii and getting more revenue from software sales. Im not saying Wii wasnt a huge success, but it wasnt a dominant force like PS2 was in its gen that catered for both casual and hardcore. And what I mean by using NES example is that the idea that power isnt important is flawed in itself, graphical power stop being important when its "just enough" for the moment the console comes out. 

Nintendo Suporting 2 systems was also a major problem.

But it doesn't really matter, take DS or 3DS also, or Switch now, fact is that power is not important for success of console. Wii didnt dominating like PS2 but it didnt need to dominate at all, fact that was best selling console of that gene is more than enuf. And talking about PS2, GC and OG Xbox were both stronger than PS2.