The Wii U has its fair share of criticism, to put it mildly. Some of its issues are, alas, tricky to rectify and here to stay. But others, thankfully, can be fixed and will be fe fixed.
Take the system load times, for example; they're a bit on the long side, are they not? Well, it's a problem that will be gone relatively soon.
The following is a video that Nintendo recently posted, that shows how long it takes to jump back to the Wii U Menu from a game, both before and after the upcoming system update:
As you can tell, it's a night and day difference. One could easily harp on Nintendo for having such a ridiculously slow system performance in the first place, but the most important thing is that it's being addressed and will soon be a thing of the past.
The upcoming update is the first of two, The second comes later this summer, and will finally give us Wii U Virtual Console. Unfortunately, it will have its own unique headache to deal with.