Did Wii U sell as much as it did because Nintendo fans buy anything or because games like Mario Kart 8, Super Smash Bros 4, Super Mario Maker & Splatoon were high quality and desirable games?
If it sold because of very dedicated fans than games like Kirby: Rainbow Curse, Animal Crossing: Amiibo Party, Paper Mario: Color Splash & Star Fox Zero should have been multimillion selling hits like the other games I listed were.
That doesn't make any sense. Nintendo always sells consoles off two things: hardware and games. And where the Wii U was lacking in hardware, it had some very good software. However, that software wasn't enough to get a lot of casuals invested in the Wii U. So who was buying the hardware to play the software? Mostly fans. They put more value on the software than other people because they are a fan of that software to a greater degree than the casual audience. I feel like that should be pretty obvious. Not sure why you thought I was implying that Nintendo fans bought anything. All I was implying is that it takes a very dedicated audience to get a console as clumsy as the Wii U to 13.5 million sales, which I don't think should be looked at as some great offense.
If you saw what I wrote in the thread earlier, the argument that Nintendo fans buy anything is nonsensical anyways because even if that were true, that's mostly due to the hard work Nintendo has put in to establish a huge following. And as you can see, that's a big reason why games like Amiibo Festival (party was the Mario Party 10 mode), Color Splash and Star Fox Zero sold less. Not only did they come out during the Wii U's most dead years, but fans weren't feeling the passion that they felt from other Nintendo games.
Edit: I think it's more complicated than fans do or don't buy anything. Mostly because the argument that fans buy anything is figurative anyways, not literal. The basis is that fans tend to buy stuff that is looked at as a worse value more than casuals do, which tends to be true for all console fanbases. However, the argument mostly falls flat because that doesn't matter. It's true for all audiences, and Nintendo earns their keep anyways considering most of their software is beloved. Not to mention, there are certainly times where the value perspective swings more towards casuals than the hardcore following.