1. No games. That is an exaggeration, because the games the WiiU had were actually good. But Nintendo got into the same problem with the switch to HD that Sony and Microsoft had: Xbox 360 and PS3 had a slow start because game development exploded in time, so they initially had a very sparse library. Same happened with WiiU, even though they made the transition much later. I remember I bought the WiiU on launch because of the 'launch window' games. Turned out the launch window was actually more than a year, as I got Pikmin 3 only so much later. For a classic launch lineup their announcement seemed good, but it was actually the lineup for a whole year, which was bad.
2. Missing focus. Or maybe bad focus. I never heard Nintendo to put so much focus in marketing on 3rd-parties. How they had designed everything for 3rd-parties. How they had partnerships, even unprecented ones (with EA). Turns out the mythical 3rd-parties abandoned the system pretty much in the first month. With the focus of the WiiU being 3rd-parties this meant the system suddenly had no focus. Compare that to Switch, for which Nintendo mentioned before launch 3rd-party support only at the side and focused on their own games and the abilities of the system. And then the 3rd-parties came afterwards.
