I would list a bunch of issues:
- You can't buy a second regular gamepad (tablet). Really, only in Japan. So if your gamepad breaks, you have to buy a second hand gamepad or get a new console. Which kind of people would want this?
- Terrible naming. Like "we" and "you"? I still don't get it. But it's a minor problem.
- Horrible battery life for the tablet.
- Bad controller ergonomics.
- Remote play was bad. You still have to be close to the console, so it's a moot point. Unless you're in Japan, most people have a dedicated gaming TV, so it's useless. It also made games have to work with a single screen, stimulating developers to avoid using the second screen for something relevant.
- Almost zero games had relevant gamepad features. It was a glorified mini-map and inventory management.
- As the gimmick was not interesting, it ended up just being a weak and expensive PS4/X1 alternative with zero 3rd party support.
The last 3 made it DOA. The Switch sells because it has a good "gimmick". Play on the go and seamlessly changes to TV mode. Local multiplayer with a single detachable controller, local MP on the go. So it has features to be different than other consoles on the same price point. Wii U didn't, so it would only have been successful if it, at least, beat the PS4 for a big margin to compensate the lack of games (right now, it would probably have to be around US$$ 150).
