This is why I said it appears thats what "most consumers" want, not specifically you.
I think it has more to do with the fact that as we get older we have less time to enjoy entertainment in comparison to when we were younger. So being able to have multiple forms of entertainment in one box(gaming, tv, music, internet, etc.) is more of a great convience instead of having to use four or more different devices for all those different forms of entertainment. But if it's not your thing then it's not your thing.Everyone, consumers and the industry, take video games for granted. Apparently games aren't good enough to stand alone, so they have to be bundled with movies, TV, music and all other kinds of media to be marketable.
My previous answer already touched on this but it's also probably because the XBO and PS4 simply do more than the Wii U does with the built in bluray players being another example. But even when you are talking about strictly gaming, if you throw out all of Microsoft's, Sony's and Nintendo's first party exclusives you are still left with alot of third party games(COD, Battlefield, UFC, Destiny, Batman: Arkham Knight, Dragon Age, Mass Effect, the next Elderscrolls, next Fallout and dozens more) that the Wii U will never see releases for. Some people complain about the Wii U sucks for whatever reasons but it basically just doesn't do as much as the other systems do. But as you already said, you could care less about the multimedia features, which is why I recommended the 3DS(which I own) or Wii U because you seem to be a big fan of Nintendo's first party games. So you should be ok with either system.The fact that the PS4 and X1 have sold more units than the older Wii U says that most people only see video games as a casual interest. Those people are really buying a PS4 or X1 to watch movies or TV shows on, with the occasional Call of Duty or Madden game. That's not really comparable to a dedicated game console.